SELECT 
  product_id, 
  feature_short_desc 
FROM 
  cscart_ab__short_desc_from_features_values 
WHERE 
  product_id IN (
    21423, 21424, 21425, 21426, 21427, 21428, 
    21429, 21430, 21431, 21432, 21433, 
    21434, 21435, 21436, 21437, 21438
  ) 
  AND lang_code = 'en' 
  AND storefront_id = 1

Query time 0.01073

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_ab__short_desc_from_features_values",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["product_id", "lang_code"],
      "rows": 16,
      "filtered": 100,
      "attached_condition": "cscart_ab__short_desc_from_features_values.storefront_id = 1 and cscart_ab__short_desc_from_features_values.product_id in (21423,21424,21425,21426,21427,21428,21429,21430,21431,21432,21433,21434,21435,21436,21437,21438) and cscart_ab__short_desc_from_features_values.lang_code = 'en'"
    }
  }
}