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 (
    89712, 89713, 89670, 88106, 88118, 88130, 
    88264, 88273, 88274, 88270, 88302, 
    88303, 89708, 89709, 89666, 88268, 
    88269, 89669, 89705, 89662, 89672, 
    89673, 88267, 89667, 89668, 89710, 
    89711, 88348, 88349, 88350, 89665, 
    88300, 88301, 88265, 88266, 88272, 
    89706, 89707, 88344, 88345, 88346, 
    88347, 89663, 89664, 89671, 89701, 
    89702, 88105
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00097

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 (89712,89713,89670,88106,88118,88130,88264,88273,88274,88270,88302,88303,89708,89709,89666,88268,88269,89669,89705,89662,89672,89673,88267,89667,89668,89710,89711,88348,88349,88350,89665,88300,88301,88265,88266,88272,89706,89707,88344,88345,88346,88347,89663,89664,89671,89701,89702,88105)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
88105 nuie Square Slimline Shower Tray 900 x 900mm - White
88106 nuie Rectangular Slimline Shower Tray 1200 x 800mm - White
88118 nuie Rectangular Slimline Shower Tray 1200 x 800mm - Grey
88130 nuie Rectangular Slimline Shower Tray 1200 x 800mm - Black
88264 nuie Slip Resistant Rectangular Slimline Shower Tray 1200 x 700mm - White
88265 nuie Slip Resistant Rectangular Slimline Shower Tray 1000 x 760mm - White
88266 nuie Slip Resistant Rectangular Slimline Shower Tray 1000 x 800mm - White
88267 nuie Slip Resistant Rectangular Slimline Shower Tray 1000 x 900mm - White
88268 nuie Slip Resistant Rectangular Slimline Shower Tray 1100 x 700mm - White
88269 nuie Slip Resistant Rectangular Slimline Shower Tray 1100 x 760mm - White
88270 nuie Slip Resistant Rectangular Slimline Shower Tray 1100 x 800mm - White
88272 nuie Slip Resistant Rectangular Slimline Shower Tray 1000 x 700mm - White
88273 nuie Slip Resistant Rectangular Slimline Shower Tray 1200 x 760mm - White
88274 nuie Slip Resistant Rectangular Slimline Shower Tray 1200 x 800mm - White
88300 nuie Slip Resistant Offset Quadrant Slimline Shower Tray Left Hand 1000 x 800mm - White
88301 nuie Slip Resistant Offset Quadrant Slimline Shower Tray Right Hand 1000 x 800mm - White
88302 nuie Slip Resistant Offset Quadrant Slimline Shower Tray Left Hand 1200 x 800mm - White
88303 nuie Slip Resistant Offset Quadrant Slimline Shower Tray Right Hand 1200 x 800mm - White
88344 nuie Rectangular Slimline Shower Tray 1300 x 800mm - White
88345 nuie Rectangular Slimline Shower Tray 1400 x 700mm - White
88346 nuie Rectangular Slimline Shower Tray 1400 x 760mm - White
88347 nuie Rectangular Slimline Shower Tray 1400 x 800mm - White
88348 nuie Rectangular Slimline Shower Tray 1400 x 900mm - White
88349 nuie Rectangular Slimline Shower Tray 1500 x 700mm - White
88350 nuie Rectangular Slimline Shower Tray 1500 x 760mm - White
89662 nuie Rectangular Slimline Shower Tray 1200 x 700mm - Slate Grey
89663 nuie Rectangular Slimline Shower Tray 1000 x 760mm - Slate Grey
89664 nuie Rectangular Slimline Shower Tray 1000 x 800mm - Slate Grey
89665 nuie Rectangular Slimline Shower Tray 1000 x 900mm - Slate Grey
89666 nuie Square Slimline Shower Tray 1000 x 1000mm - Slate Grey
89667 nuie Rectangular Slimline Shower Tray 1100 x 700mm - Slate Grey
89668 nuie Rectangular Slimline Shower Tray 1100 x 760mm - Slate Grey
89669 nuie Rectangular Slimline Shower Tray 1100 x 800mm - Slate Grey
89670 nuie Rectangular Slimline Shower Tray 1100 x 900mm - Slate Grey
89671 nuie Rectangular Slimline Shower Tray 1000 x 700mm - Slate Grey
89672 nuie Rectangular Slimline Shower Tray 1200 x 760mm - Slate Grey
89673 nuie Rectangular Slimline Shower Tray 1200 x 800mm - Slate Grey
89701 nuie Offset Quadrant Slimline Shower Tray Left Hand 900 x 800mm - Slate Grey
89702 nuie Offset Quadrant Slimline Shower Tray Right Hand 900 x 800mm - Slate Grey
89705 nuie Quadrant Slimline Shower Tray 1000 x 1000mm - Slate Grey
89706 nuie Offset Quadrant Slimline Shower Tray Left Hand 1000 x 800mm - Slate Grey
89707 nuie Offset Quadrant Slimline Shower Tray Right Hand 1000 x 800mm - Slate Grey
89708 nuie Offset Quadrant Slimline Shower Tray Left Hand 1000 x 900mm - Slate Grey
89709 nuie Offset Quadrant Slimline Shower Tray Right Hand 1000 x 900mm - Slate Grey
89710 nuie Offset Quadrant Slimline Shower Tray Left Hand 1200 x 800mm - Slate Grey
89711 nuie Offset Quadrant Slimline Shower Tray Right Hand 1200 x 800mm - Slate Grey
89712 nuie Offset Quadrant Slimline Shower Tray Left Hand 1200 x 900mm - Slate Grey
89713 nuie Offset Quadrant Slimline Shower Tray Right Hand 1200 x 900mm - Slate Grey