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 (
    96995, 96996, 96997, 96998, 96999, 97000, 
    97001, 97002, 97003, 97004, 97005, 
    97006, 97007, 97008, 97009, 97010, 
    97083, 97219, 97220, 97221, 97222, 
    97223, 97224, 97225, 97226, 97227, 
    97567, 97570, 97573, 97574, 97575, 
    97576, 97577, 97578, 97579, 97580, 
    97581, 97582, 97583, 97584, 97585, 
    97586, 97682, 97683, 97684, 97685, 
    97686, 97687
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00089

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "26.88"
    },
    "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": "22.08",
        "eval_cost": "4.80",
        "prefix_cost": "26.88",
        "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 (96995,96996,96997,96998,96999,97000,97001,97002,97003,97004,97005,97006,97007,97008,97009,97010,97083,97219,97220,97221,97222,97223,97224,97225,97226,97227,97567,97570,97573,97574,97575,97576,97577,97578,97579,97580,97581,97582,97583,97584,97585,97586,97682,97683,97684,97685,97686,97687)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
96995
96996
96997
96998
96999
97000
97001
97002
97003
97004
97005
97006
97007
97008
97009
97010
97083
97219
97220
97221
97222
97223
97224
97225
97226
97227
97567
97570
97573
97574
97575
97576
97577
97578
97579
97580
97581
97582
97583
97584
97585
97586
97682
97683
97684
97685
97686
97687