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 (
    86062, 86064, 86065, 86066, 86068, 85040, 
    85041, 92893, 92894, 93002, 93003, 
    93004, 93005, 93006, 93007, 93008, 
    93009, 93010, 93011, 93012, 93013, 
    93014, 93015, 93341, 93342, 93343, 
    93344, 93345, 93346, 93347, 93348, 
    93349, 93350, 93351, 93352, 93353, 
    93354, 93355, 93750, 93751, 93752, 
    93848, 93849, 93886, 93887, 93888, 
    93889, 93890
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00107

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 (86062,86064,86065,86066,86068,85040,85041,92893,92894,93002,93003,93004,93005,93006,93007,93008,93009,93010,93011,93012,93013,93014,93015,93341,93342,93343,93344,93345,93346,93347,93348,93349,93350,93351,93352,93353,93354,93355,93750,93751,93752,93848,93849,93886,93887,93888,93889,93890)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
85040 nuie Accessories L-Shaped Bamboo Drawer Organiser - Bamboo
85041 nuie Accessories Straight Bamboo Drawer Organiser - Bamboo
86062 nuie Handles 328mm D Handle Brushed Brass - Brushed Brass
86064 nuie Handles Finger Pull Handle 150mm - Brushed Brass
86065 nuie Handles Finger Pull Handle 300mm - Brushed Brass
86066 nuie Handles Finger Pull Handle 500mm - Brushed Brass
86068 nuie Handles Rounded D Handle 160mm Centres - Chrome
92893
92894
93002
93003
93004
93005
93006
93007
93008
93009
93010
93011
93012
93013
93014
93015
93341
93342
93343
93344
93345
93346
93347
93348
93349
93350
93351
93352
93353
93354
93355
93750
93751
93752
93848
93849
93886
93887
93888
93889
93890