SELECT 
  thumb_up 
FROM 
  kl_likes 
WHERE 
  user_id = 21551 
  AND target_id = 2442 
  AND type = 'Video_Video'

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "1.09"
    },
    "table": {
      "table_name": "kl_likes",
      "access_type": "ref",
      "possible_keys": [
        "user_id",
        "type"
      ],
      "key": "user_id",
      "used_key_parts": [
        "user_id"
      ],
      "key_length": "4",
      "ref": [
        "const"
      ],
      "rows_examined_per_scan": 1,
      "rows_produced_per_join": 0,
      "filtered": "5.00",
      "cost_info": {
        "read_cost": "0.99",
        "eval_cost": "0.01",
        "prefix_cost": "1.09",
        "data_read_per_join": "8"
      },
      "used_columns": [
        "user_id",
        "target_id",
        "type",
        "thumb_up"
      ],
      "attached_condition": "((`cscart_db`.`kl_likes`.`target_id` = 2442) and (`cscart_db`.`kl_likes`.`type` = 'Video_Video'))"
    }
  }
}