SELECT 
  product_id, 
  feature_id, 
  variant_id 
FROM 
  cscart_product_features_values 
WHERE 
  product_id IN (
    12348, 12347, 12346, 12345, 12344, 12343, 
    12342, 12341, 12340, 12339, 12338, 
    12337, 12336, 12335, 12334, 12333, 
    12332, 12331, 12330, 12329, 12328, 
    12327, 12326, 12325, 12324, 12323, 
    12322, 12321, 12320, 12319, 12318, 
    12317, 12316, 12315, 12314, 12313, 
    12312, 12311, 12310, 12309, 12308, 
    12307, 12306, 12305, 12304, 12303, 
    12302, 12301, 12300, 12299, 12298, 
    12297, 12296, 12295, 12294, 12293, 
    12292, 12291, 12290, 12289, 12288, 
    12287, 12286, 12285, 12284, 12283, 
    12282, 12281, 12280, 12279, 12278, 
    12277, 12276, 12275, 12274, 12273, 
    12272, 12271, 12270, 12269, 12268, 
    12267, 12266, 12265, 12264, 12263, 
    12262, 12261, 12260, 12259
  ) 
  AND feature_id IN (627, 628, 624, 625, 553) 
  AND lang_code = 'en'

Query time 0.01358

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "14.62"
    },
    "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": 45,
      "rows_produced_per_join": 45,
      "filtered": "100.00",
      "using_index_for_skip_scan": true,
      "cost_info": {
        "read_cost": "10.12",
        "eval_cost": "4.50",
        "prefix_cost": "14.62",
        "data_read_per_join": "34K"
      },
      "used_columns": [
        "feature_id",
        "product_id",
        "variant_id",
        "lang_code"
      ],
      "attached_condition": "((`test2_gaseus`.`cscart_product_features_values`.`product_id` in (12348,12347,12346,12345,12344,12343,12342,12341,12340,12339,12338,12337,12336,12335,12334,12333,12332,12331,12330,12329,12328,12327,12326,12325,12324,12323,12322,12321,12320,12319,12318,12317,12316,12315,12314,12313,12312,12311,12310,12309,12308,12307,12306,12305,12304,12303,12302,12301,12300,12299,12298,12297,12296,12295,12294,12293,12292,12291,12290,12289,12288,12287,12286,12285,12284,12283,12282,12281,12280,12279,12278,12277,12276,12275,12274,12273,12272,12271,12270,12269,12268,12267,12266,12265,12264,12263,12262,12261,12260,12259)) and (`test2_gaseus`.`cscart_product_features_values`.`feature_id` in (627,628,624,625,553)) and (`test2_gaseus`.`cscart_product_features_values`.`lang_code` = 'en'))"
    }
  }
}