SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.short_description, 
  IF(
    cscart_product_descriptions.short_description = '' 
    OR cscart_product_descriptions.short_description IS NULL, 
    cscart_product_descriptions.full_description, 
    ''
  ) AS full_description 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    220026, 220035, 220028, 220016, 220024, 
    220020, 427782, 286468, 286472, 286478, 
    286465, 286467, 286479, 286475, 286473, 
    286469, 286466, 286470, 286471, 286474, 
    286476
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00123

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "29.44"
    },
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "product_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id",
        "lang_code"
      ],
      "key_length": "9",
      "rows_examined_per_scan": 21,
      "rows_produced_per_join": 21,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "25.25",
        "eval_cost": "4.20",
        "prefix_cost": "29.45",
        "data_read_per_join": "143K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`webmarco`.`cscart_product_descriptions`.`product_id` in (220026,220035,220028,220016,220024,220020,427782,286468,286472,286478,286465,286467,286479,286475,286473,286469,286466,286470,286471,286474,286476)) and (`webmarco`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}