SELECT 
  product_id, 
  feature_short_desc 
FROM 
  cscart_ab__short_desc_from_features_values 
WHERE 
  product_id IN (
    20605, 20606, 20607, 20608, 20609, 20610, 
    20611, 20612, 20613, 20614, 20615, 
    20616, 20617, 20618, 20619, 20620
  ) 
  AND lang_code = 'en' 
  AND storefront_id = 1

Query time 0.00034

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 (20605,20606,20607,20608,20609,20610,20611,20612,20613,20614,20615,20616,20617,20618,20619,20620) and cscart_ab__short_desc_from_features_values.lang_code = 'en'"
    }
  }
}