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 (
    92893, 92894, 92913, 92914, 92915, 92916, 
    92917, 92918, 92919, 92920, 92921, 
    93002, 93003, 93004, 93005, 93006, 
    93007, 93008, 93009, 93010, 93011, 
    93012, 93013, 93014, 93015, 93282, 
    93283, 93284, 93285, 93286
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00074

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 (92893,92894,92913,92914,92915,92916,92917,92918,92919,92920,92921,93002,93003,93004,93005,93006,93007,93008,93009,93010,93011,93012,93013,93014,93015,93282,93283,93284,93285,93286)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
92893
92894
92913
92914
92915
92916
92917
92918
92919
92920
92921
93002
93003
93004
93005
93006
93007
93008
93009
93010
93011
93012
93013
93014
93015
93282
93283
93284
93285
93286