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 (
    85136, 85182, 85228, 85048, 85049, 85134, 
    85135, 85180, 85181, 85226, 85227, 
    85044, 86463, 86464, 86605, 86606, 
    86674, 86675, 85042, 85043, 86603, 
    86672, 86461, 86462, 86604, 86673, 
    86601, 86602, 86670, 86671, 86599, 
    86600, 86668, 86669, 89958, 89959, 
    89956, 89957, 89954, 89955, 89952, 
    89953, 86477, 86478, 86615, 86616, 
    86684, 86685
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00098

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 (85136,85182,85228,85048,85049,85134,85135,85180,85181,85226,85227,85044,86463,86464,86605,86606,86674,86675,85042,85043,86603,86672,86461,86462,86604,86673,86601,86602,86670,86671,86599,86600,86668,86669,89958,89959,89956,89957,89954,89955,89952,89953,86477,86478,86615,86616,86684,86685)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}