SELECT 
  product_id, 
  feature_id, 
  variant_id 
FROM 
  cscart_product_features_values 
WHERE 
  product_id IN (
    42023, 42022, 42021, 42020, 42019, 42018, 
    42017, 42016, 42015, 42014, 42013, 
    41945
  ) 
  AND feature_id IN (24288) 
  AND lang_code = 'vi'

Query time 0.00405

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": "idx_product_feature_variant_id",
          "key_length": "12",
          "used_key_parts": ["product_id", "feature_id", "lang_code"],
          "rows": 12,
          "filtered": 100,
          "attached_condition": "cscart_product_features_values.feature_id = 24288 and cscart_product_features_values.product_id in (42023,42022,42021,42020,42019,42018,42017,42016,42015,42014,42013,41945) and cscart_product_features_values.lang_code = 'vi'",
          "using_index": true
        }
      }
    ]
  }
}

Result

product_id feature_id variant_id
41945 24288 84622
42013 24288 84631
42014 24288 84632
42015 24288 84633
42016 24288 84623
42017 24288 84624
42018 24288 84625
42019 24288 84626
42020 24288 84627
42021 24288 84628
42022 24288 84629
42023 24288 84630