SELECT 
  product_id, 
  feature_id, 
  variant_id 
FROM 
  cscart_product_features_values 
WHERE 
  product_id IN (
    45571, 45740, 45741, 45742, 45743, 45744, 
    45745, 45746, 45747, 45748, 45749, 
    45750, 45751, 45752, 45753, 45754, 
    45755, 45756, 45757, 45758
  ) 
  AND feature_id IN (24634) 
  AND lang_code = 'vi'

Query time 0.00609

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": 38,
          "filtered": 55.26315689,
          "attached_condition": "cscart_product_features_values.feature_id = 24634 and cscart_product_features_values.product_id in (45571,45740,45741,45742,45743,45744,45745,45746,45747,45748,45749,45750,45751,45752,45753,45754,45755,45756,45757,45758) and cscart_product_features_values.lang_code = 'vi'",
          "using_index": true
        }
      }
    ]
  }
}