SELECT 
  product_id, 
  feature_id, 
  variant_id 
FROM 
  cscart_product_features_values 
WHERE 
  product_id IN (
    49894, 49895, 49896, 49897, 49898, 49899, 
    49900, 49901, 49902, 49903, 49904, 
    49905
  ) 
  AND feature_id IN (24144, 25095) 
  AND lang_code = 'vi'

Query time 0.01161

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "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",
          "key_length": "6",
          "used_key_parts": ["feature_id", "product_id"],
          "rows": 35,
          "filtered": 51.5835762,
          "attached_condition": "cscart_product_features_values.product_id in (49894,49895,49896,49897,49898,49899,49900,49901,49902,49903,49904,49905) and cscart_product_features_values.feature_id in (24144,25095) and cscart_product_features_values.lang_code = 'vi'",
          "using_index": true
        }
      }
    ]
  }
}

Result

product_id feature_id variant_id
49894 24144 84152
49895 24144 84152
49896 24144 84154
49897 24144 84154
49898 24144 84155
49899 24144 84155
49900 24144 87601
49901 24144 87601
49902 24144 87602
49903 24144 87602
49904 24144 84153
49905 24144 84153
49894 25095 87603
49895 25095 87604
49896 25095 87603
49897 25095 87604
49898 25095 87603
49899 25095 87604
49900 25095 87603
49901 25095 87604
49902 25095 87603
49903 25095 87604
49904 25095 87603
49905 25095 87604