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 (
    87903, 87908, 87914, 87893, 87913, 87917, 
    87915, 87907, 95833, 95834, 95835, 
    95836, 95837, 95838, 95839, 95840, 
    95841, 95842, 95843, 95844, 95845, 
    95846, 95847, 95848, 95849, 95850, 
    95851, 95852, 95853, 95854
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00071

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "13.52"
    },
    "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": 30,
      "rows_produced_per_join": 30,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "10.52",
        "eval_cost": "3.00",
        "prefix_cost": "13.52",
        "data_read_per_join": "114K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (87903,87908,87914,87893,87913,87917,87915,87907,95833,95834,95835,95836,95837,95838,95839,95840,95841,95842,95843,95844,95845,95846,95847,95848,95849,95850,95851,95852,95853,95854)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
87893 nuie Round Vessel 460 x 460 x 220mm
87903 nuie Square Vessel 365 x 365 x 120mm
87907 nuie Round Vessel 358 x 368 x 137mm
87908 nuie Oval Vessel 490 x 320 x 135mm
87913 nuie Semi-Recessed Basin 480 x 370 x 130mm
87914 nuie Rectangular Vessel 500 x 350 x 120mm
87915 nuie Rectangular Vessel 365 x 235 x 120mm
87917 nuie Rectangular Vessel 520 x 340 x 152mm
95833
95834
95835
95836
95837
95838
95839
95840
95841
95842
95843
95844
95845
95846
95847
95848
95849
95850
95851
95852
95853
95854