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 (
    88573, 92554, 92597, 92598, 92599, 92600, 
    92601, 92602, 92603, 92604, 92605, 
    92606, 92607, 92608, 92609, 92610, 
    92611, 92612, 92613, 92614, 92615, 
    92616, 92617, 92618, 92619, 92620, 
    92621, 92622, 92623, 92624, 92625, 
    92626, 92627, 92628, 92629, 92630, 
    92631, 92632, 92633, 92634, 92635, 
    92636, 92637, 92638, 92639, 92640, 
    92641, 92642
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00089

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 (88573,92554,92597,92598,92599,92600,92601,92602,92603,92604,92605,92606,92607,92608,92609,92610,92611,92612,92613,92614,92615,92616,92617,92618,92619,92620,92621,92622,92623,92624,92625,92626,92627,92628,92629,92630,92631,92632,92633,92634,92635,92636,92637,92638,92639,92640,92641,92642)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
88573 Hudson Reed Fusion WC Unit Top 500mm - Gloss White
92554 Cloakroom Pack Floor Standing Saturn Furniture Pack with Round Basin
92597
92598
92599
92600
92601
92602
92603
92604
92605
92606
92607
92608
92609
92610
92611
92612
92613
92614
92615
92616
92617
92618
92619
92620
92621
92622
92623
92624
92625
92626
92627
92628
92629
92630
92631
92632
92633
92634
92635
92636
92637
92638
92639
92640
92641
92642