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 (
    90616, 90617, 90622, 90623, 90724, 90726, 
    90716, 90722, 90592, 90593, 92534, 
    89243, 89244, 89253, 89254, 90588, 
    90590, 90657, 90642, 92533, 90664, 
    90665, 90670, 90671, 89245, 89246, 
    89247, 89248, 90589, 90591, 90606, 
    90607, 90612, 90613, 90599, 90715, 
    90721, 89249, 89250, 89251, 89252, 
    90709, 90711, 90654, 90655, 90660, 
    90661, 90698
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "21.63"
    },
    "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": 48,
      "rows_produced_per_join": 48,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "16.83",
        "eval_cost": "4.80",
        "prefix_cost": "21.63",
        "data_read_per_join": "183K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (90616,90617,90622,90623,90724,90726,90716,90722,90592,90593,92534,89243,89244,89253,89254,90588,90590,90657,90642,92533,90664,90665,90670,90671,89245,89246,89247,89248,90589,90591,90606,90607,90612,90613,90599,90715,90721,89249,89250,89251,89252,90709,90711,90654,90655,90660,90661,90698)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}