SELECT 
  product_id, 
  feature_id, 
  variant_id 
FROM 
  cscart_product_features_values 
WHERE 
  product_id IN (
    62270, 62271, 62272, 62273, 62274, 62275, 
    62276, 62277, 62278, 62279, 62280, 
    62281, 62282, 62283, 62284, 62285, 
    62286, 62287, 62288, 62289, 62290, 
    62291, 62292, 62293
  ) 
  AND feature_id IN (1444, 1445, 1446) 
  AND lang_code = 'en'

Query time 0.00236

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "3.82"
    },
    "table": {
      "table_name": "cscart_product_features_values",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "fl",
        "lang_code",
        "product_id",
        "fpl",
        "idx_product_feature_variant_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "feature_id",
        "product_id",
        "variant_id",
        "lang_code"
      ],
      "key_length": "15",
      "rows_examined_per_scan": 8,
      "rows_produced_per_join": 8,
      "filtered": "100.00",
      "using_index_for_skip_scan": true,
      "cost_info": {
        "read_cost": "3.02",
        "eval_cost": "0.80",
        "prefix_cost": "3.82",
        "data_read_per_join": "6K"
      },
      "used_columns": [
        "feature_id",
        "product_id",
        "variant_id",
        "lang_code"
      ],
      "attached_condition": "((`cscartdb`.`cscart_product_features_values`.`product_id` in (62270,62271,62272,62273,62274,62275,62276,62277,62278,62279,62280,62281,62282,62283,62284,62285,62286,62287,62288,62289,62290,62291,62292,62293)) and (`cscartdb`.`cscart_product_features_values`.`feature_id` in (1444,1445,1446)) and (`cscartdb`.`cscart_product_features_values`.`lang_code` = 'en'))"
    }
  }
}