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 (
    87372, 89543, 82487, 89532, 89540, 82492, 
    87371, 89546, 89538, 89554, 91481, 
    85620, 85634, 91480, 89544, 85618, 
    89542, 85616, 85619, 85633, 82491, 
    89563, 85617, 82490, 85615, 82489, 
    91478, 82488, 91479, 85638, 85637, 
    85636, 85635, 92560, 92561, 92562, 
    92563, 92564, 92565, 92566, 92567, 
    92568, 92569, 92570, 92571, 92572, 
    92573, 92574
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00104

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "21.62"
    },
    "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": "16.82",
        "eval_cost": "4.80",
        "prefix_cost": "21.62",
        "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 (87372,89543,82487,89532,89540,82492,87371,89546,89538,89554,91481,85620,85634,91480,89544,85618,89542,85616,85619,85633,82491,89563,85617,82490,85615,82489,91478,82488,91479,85638,85637,85636,85635,92560,92561,92562,92563,92564,92565,92566,92567,92568,92569,92570,92571,92572,92573,92574)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}