SELECT 
  product_id, 
  feature_id, 
  variant_id 
FROM 
  cscart_product_features_values 
WHERE 
  product_id IN (
    12483, 12484, 12485, 12486, 12487, 12488, 
    12489, 12490, 12491, 12482, 12481, 
    12480, 12479, 12478, 12477, 12476, 
    12475, 12474, 12473, 12472, 12471, 
    12470, 12469, 12468, 12467, 12466, 
    12465, 12464, 12493, 12492
  ) 
  AND feature_id IN (553, 628, 627, 624, 625) 
  AND lang_code = 'en'

Query time 0.00641

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "11.09"
    },
    "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": 32,
      "rows_produced_per_join": 32,
      "filtered": "100.00",
      "using_index_for_skip_scan": true,
      "cost_info": {
        "read_cost": "7.89",
        "eval_cost": "3.20",
        "prefix_cost": "11.09",
        "data_read_per_join": "24K"
      },
      "used_columns": [
        "feature_id",
        "product_id",
        "variant_id",
        "lang_code"
      ],
      "attached_condition": "((`test2_gaseus`.`cscart_product_features_values`.`product_id` in (12483,12484,12485,12486,12487,12488,12489,12490,12491,12482,12481,12480,12479,12478,12477,12476,12475,12474,12473,12472,12471,12470,12469,12468,12467,12466,12465,12464,12493,12492)) and (`test2_gaseus`.`cscart_product_features_values`.`feature_id` in (553,628,627,624,625)) and (`test2_gaseus`.`cscart_product_features_values`.`lang_code` = 'en'))"
    }
  }
}