SELECT 
  product_id, 
  feature_short_desc 
FROM 
  cscart_ab__short_desc_from_features_values 
WHERE 
  product_id IN (
    21679, 21680, 21681, 21682, 21683, 21684, 
    21685, 21686, 21687, 21688, 21689, 
    21690, 21691, 21692, 21693, 21694
  ) 
  AND lang_code = 'en' 
  AND storefront_id = 1

Query time 0.00028

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 (21679,21680,21681,21682,21683,21684,21685,21686,21687,21688,21689,21690,21691,21692,21693,21694) and cscart_ab__short_desc_from_features_values.lang_code = 'en'"
    }
  }
}