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 (
    85173, 85219, 85265, 86173, 86174, 86196, 
    86197, 82834, 82836, 82907, 82909, 
    82980, 82982, 83394, 83396, 83404, 
    83406, 85127, 86514, 86515, 86790, 
    86791, 85059, 85145, 85191, 85237, 
    82831, 82904, 82977, 83391, 83401, 
    89808, 89810, 89860, 89862, 89932, 
    89934, 91498, 91500, 86129, 86130, 
    86152, 86153, 85099, 85296, 85298, 
    85393, 85395
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00068

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 (85173,85219,85265,86173,86174,86196,86197,82834,82836,82907,82909,82980,82982,83394,83396,83404,83406,85127,86514,86515,86790,86791,85059,85145,85191,85237,82831,82904,82977,83391,83401,89808,89810,89860,89862,89932,89934,91498,91500,86129,86130,86152,86153,85099,85296,85298,85393,85395)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}