SELECT 
  product_id, 
  feature_short_desc 
FROM 
  cscart_ab__short_desc_from_features_values 
WHERE 
  product_id IN (
    21695, 21696, 21697, 21698, 21699, 21700, 
    21701, 21702, 21703, 21704, 21705, 
    21706, 21707, 21708, 21709, 21710
  ) 
  AND lang_code = 'en' 
  AND storefront_id = 1

Query time 0.00024

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 (21695,21696,21697,21698,21699,21700,21701,21702,21703,21704,21705,21706,21707,21708,21709,21710) and cscart_ab__short_desc_from_features_values.lang_code = 'en'"
    }
  }
}