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 (
    88681, 88726, 88728, 88773, 88775, 88570, 
    88573, 92554, 92597, 92598, 92599, 
    92600, 92601, 92602, 92603, 92604, 
    92605, 92606, 92607, 92608, 92609, 
    92610, 92611, 92612, 92613, 92614, 
    92615, 92616, 92617, 92618
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "16.21"
    },
    "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": 30,
      "rows_produced_per_join": 30,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "13.22",
        "eval_cost": "3.00",
        "prefix_cost": "16.22",
        "data_read_per_join": "114K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (88681,88726,88728,88773,88775,88570,88573,92554,92597,92598,92599,92600,92601,92602,92603,92604,92605,92606,92607,92608,92609,92610,92611,92612,92613,92614,92615,92616,92617,92618)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}