SELECT 
  cscart_products.*, 
  cscart_product_descriptions.*, 
  MIN(
    IF(
      cscart_product_prices.percentage_discount = 0, 
      cscart_product_prices.price, 
      cscart_product_prices.price - (
        cscart_product_prices.price * cscart_product_prices.percentage_discount
      )/ 100
    )
  ) as price, 
  GROUP_CONCAT(
    CASE WHEN (
      cscart_products_categories.link_type = 'M'
    ) THEN CONCAT(
      cscart_products_categories.category_id, 
      'M'
    ) ELSE cscart_products_categories.category_id END 
    ORDER BY 
      cscart_categories.company_id = 1 DESC, 
      (
        cscart_products_categories.link_type = 'M'
      ) DESC, 
      cscart_products_categories.category_position ASC, 
      cscart_products_categories.category_id ASC
  ) as category_ids, 
  popularity.total as popularity, 
  IF(
    shared_prices.product_id IS NOT NULL, 
    MIN(
      IF(
        shared_prices.percentage_discount = 0, 
        shared_prices.price, 
        shared_prices.price - (
          shared_prices.price * shared_prices.percentage_discount
        )/ 100
      )
    ), 
    MIN(
      IF(
        cscart_product_prices.percentage_discount = 0, 
        cscart_product_prices.price, 
        cscart_product_prices.price - (
          cscart_product_prices.price * cscart_product_prices.percentage_discount
        )/ 100
      )
    )
  ) as price, 
  companies.company as company_name, 
  cscart_products.is_returnable, 
  cscart_products.return_period, 
  cscart_product_sales.amount as sales_amount, 
  cscart_seo_names.name as seo_name, 
  cscart_seo_names.path as seo_path, 
  cscart_discussion.type as discussion_type 
FROM 
  cscart_products 
  LEFT JOIN cscart_product_prices ON cscart_product_prices.product_id = cscart_products.product_id 
  AND cscart_product_prices.lower_limit = 1 
  AND cscart_product_prices.usergroup_id IN (0, 0, 1) 
  LEFT JOIN cscart_product_descriptions ON cscart_product_descriptions.product_id = cscart_products.product_id 
  AND cscart_product_descriptions.lang_code = 'ru' 
  LEFT JOIN cscart_ult_product_prices shared_prices ON shared_prices.product_id = cscart_products.product_id 
  AND shared_prices.company_id = 1 
  AND shared_prices.lower_limit = 1 
  AND shared_prices.usergroup_id IN (0, 0, 1) 
  LEFT JOIN cscart_companies as companies ON companies.company_id = cscart_products.company_id 
  INNER JOIN cscart_products_categories ON cscart_products_categories.product_id = cscart_products.product_id 
  INNER JOIN cscart_categories ON cscart_categories.category_id = cscart_products_categories.category_id 
  AND cscart_categories.company_id = 1 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND (
    cscart_products.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_products.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_products.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
  AND cscart_products.status IN ('A', 'H') 
  LEFT JOIN cscart_product_popularity as popularity ON popularity.product_id = cscart_products.product_id 
  LEFT JOIN cscart_product_sales ON cscart_product_sales.product_id = cscart_products.product_id 
  AND cscart_product_sales.category_id = 275 
  LEFT JOIN cscart_seo_names ON cscart_seo_names.object_id = 300 
  AND cscart_seo_names.type = 'p' 
  AND cscart_seo_names.dispatch = '' 
  AND cscart_seo_names.lang_code = 'ru' 
  AND cscart_seo_names.company_id = 1 
  LEFT JOIN cscart_discussion ON cscart_discussion.object_id = cscart_products.product_id 
  AND cscart_discussion.object_type = 'P' 
WHERE 
  cscart_products.product_id = 300 
  AND (
    companies.status = 'A' 
    OR cscart_products.company_id = 0
  ) 
GROUP BY 
  cscart_products.product_id

Query time 0.00184

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_products",
      "access_type": "const",
      "possible_keys": ["PRIMARY", "status"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "ref": ["const"],
      "rows": 1,
      "filtered": 100
    },
    "table": {
      "table_name": "popularity",
      "access_type": "const",
      "possible_keys": ["PRIMARY", "total"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "ref": ["const"],
      "rows": 1,
      "filtered": 100
    },
    "table": {
      "table_name": "cscart_product_sales",
      "access_type": "const",
      "possible_keys": ["PRIMARY", "pa"],
      "key": "PRIMARY",
      "key_length": "6",
      "used_key_parts": ["category_id", "product_id"],
      "ref": ["const", "const"],
      "rows": 0,
      "filtered": 0,
      "unique_row_not_found": true
    },
    "table": {
      "table_name": "cscart_product_prices",
      "access_type": "ref",
      "possible_keys": ["usergroup", "product_id", "lower_limit", "usergroup_id"],
      "key": "product_id",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "ref": ["const"],
      "rows": 1,
      "filtered": 100,
      "attached_condition": "trigcond(cscart_product_prices.lower_limit = 1 and cscart_product_prices.usergroup_id in (0,0,1))"
    },
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "const",
      "possible_keys": ["PRIMARY", "product_id"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["product_id", "lang_code"],
      "ref": ["const", "const"],
      "rows": 1,
      "filtered": 100,
      "attached_condition": "trigcond(cscart_product_descriptions.lang_code = 'ru')"
    },
    "table": {
      "table_name": "shared_prices",
      "access_type": "ref",
      "possible_keys": [
        "usergroup",
        "product_id",
        "company_id",
        "lower_limit",
        "usergroup_id"
      ],
      "key": "product_id",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "ref": ["const"],
      "rows": 1,
      "filtered": 100,
      "attached_condition": "trigcond(shared_prices.company_id = 1 and shared_prices.lower_limit = 1 and shared_prices.usergroup_id in (0,0,1))"
    },
    "table": {
      "table_name": "companies",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "4",
      "used_key_parts": ["company_id"],
      "ref": ["const"],
      "rows": 1,
      "filtered": 100,
      "attached_condition": "trigcond(companies.`status` = 'A')"
    },
    "table": {
      "table_name": "cscart_products_categories",
      "access_type": "ref",
      "possible_keys": ["PRIMARY", "pt"],
      "key": "pt",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "ref": ["const"],
      "rows": 2,
      "filtered": 100
    },
    "table": {
      "table_name": "cscart_categories",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY", "c_status", "p_category_id"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["category_id"],
      "ref": ["orbit_cscart_orbit_cscart.cscart_products_categories.category_id"],
      "rows": 1,
      "filtered": 100,
      "attached_condition": "cscart_categories.company_id = 1 and (cscart_categories.usergroup_ids = '' or find_in_set(0,cscart_categories.usergroup_ids) or find_in_set(1,cscart_categories.usergroup_ids)) and cscart_categories.`status` in ('A','H')"
    },
    "table": {
      "table_name": "cscart_seo_names",
      "access_type": "const",
      "possible_keys": ["PRIMARY", "dispatch"],
      "key": "PRIMARY",
      "key_length": "210",
      "used_key_parts": [
        "object_id",
        "type",
        "dispatch",
        "lang_code",
        "company_id"
      ],
      "ref": ["const", "const", "const", "const", "const"],
      "rows": 1,
      "filtered": 100,
      "attached_condition": "trigcond(cscart_seo_names.`type` = 'p' and cscart_seo_names.dispatch = '' and cscart_seo_names.lang_code = 'ru')"
    },
    "table": {
      "table_name": "cscart_discussion",
      "access_type": "ref",
      "possible_keys": ["object_id"],
      "key": "object_id",
      "key_length": "6",
      "used_key_parts": ["object_id", "object_type"],
      "ref": ["const", "const"],
      "rows": 2,
      "filtered": 100,
      "attached_condition": "trigcond(cscart_discussion.object_type = 'P')"
    }
  }
}