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 (
    97553, 97554, 97555, 97556, 97557, 97558, 
    97559, 97560, 97561, 97562, 97563, 
    97564, 97565, 97566, 97568, 97569, 
    97571, 97572, 97587, 97588, 97589, 
    97590, 97591, 97592, 97593, 97594, 
    97595, 97596, 97597, 97598, 97599, 
    97600, 97601, 97602, 97603, 97604, 
    97605, 97606, 97607, 97713, 97714, 
    97715, 97953, 97954, 97955, 97956, 
    97957, 97958
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00093

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 (97553,97554,97555,97556,97557,97558,97559,97560,97561,97562,97563,97564,97565,97566,97568,97569,97571,97572,97587,97588,97589,97590,97591,97592,97593,97594,97595,97596,97597,97598,97599,97600,97601,97602,97603,97604,97605,97606,97607,97713,97714,97715,97953,97954,97955,97956,97957,97958)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
97553
97554
97555
97556
97557
97558
97559
97560
97561
97562
97563
97564
97565
97566
97568
97569
97571
97572
97587
97588
97589
97590
97591
97592
97593
97594
97595
97596
97597
97598
97599
97600
97601
97602
97603
97604
97605
97606
97607
97713
97714
97715
97953
97954
97955
97956
97957
97958