SELECT 
  q_product_descriptions.product_id, 
  q_product_descriptions.short_description, 
  IF(
    q_product_descriptions.short_description = '', 
    q_product_descriptions.full_description, 
    ''
  ) AS full_description 
FROM 
  q_product_descriptions 
WHERE 
  q_product_descriptions.product_id IN (
    32590, 32591, 32592, 32593, 32594, 32595, 
    32596, 32597, 32598, 32599, 32600, 
    32601, 32602, 32603, 32604, 32605, 
    32606, 32607, 32608, 32609, 32610, 
    32611, 32612, 32613, 32614, 32615, 
    32616, 32617, 32618, 32619, 32620, 
    32621
  ) 
  AND q_product_descriptions.lang_code = 'en'

Query time 0.00070

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "76.81"
    },
    "table": {
      "table_name": "q_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": 32,
      "rows_produced_per_join": 32,
      "filtered": "100.00",
      "index_condition": "((`portal`.`q_product_descriptions`.`product_id` in (32590,32591,32592,32593,32594,32595,32596,32597,32598,32599,32600,32601,32602,32603,32604,32605,32606,32607,32608,32609,32610,32611,32612,32613,32614,32615,32616,32617,32618,32619,32620,32621)) and (`portal`.`q_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "70.41",
        "eval_cost": "6.40",
        "prefix_cost": "76.81",
        "data_read_per_join": "122K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ]
    }
  }
}