SELECT 
  product_id 
FROM 
  cscart_cp_video_product_links 
WHERE 
  video_id = 6 
  AND `type` = 'T'

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_cp_video_product_links",
      "access_type": "index",
      "key": "PRIMARY",
      "key_length": "12",
      "used_key_parts": ["product_id", "video_id", "type"],
      "rows": 15,
      "filtered": 100,
      "attached_condition": "cscart_cp_video_product_links.video_id = 6 and cscart_cp_video_product_links.`type` = 'T'",
      "using_index": true
    }
  }
}