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 (
    88074, 88069, 87878, 88075, 88025, 84696, 
    88938, 87996, 84699, 88516, 88519, 
    88073, 88940, 88040, 84703, 84706, 
    88082, 91053, 88941, 87958, 88068, 
    87951, 88067, 88512, 88077, 88141, 
    88144, 88939, 87986, 87946, 87947, 
    87949, 88043, 87956, 89982, 89983, 
    89984, 88081, 84702, 84705, 91052, 
    88003, 88046, 88080, 84697, 84698, 
    88028, 88140
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00095

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 (88074,88069,87878,88075,88025,84696,88938,87996,84699,88516,88519,88073,88940,88040,84703,84706,88082,91053,88941,87958,88068,87951,88067,88512,88077,88141,88144,88939,87986,87946,87947,87949,88043,87956,89982,89983,89984,88081,84702,84705,91052,88003,88046,88080,84697,84698,88028,88140)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
84696 nuie 1 Tap Hole Ceramic Basin with Deep 40mm Profile 800mm
84697 nuie Arno Compact 500mm Ceramic Basin 1 Tap Hole - White
84698 nuie Arno Compact 600mm Ceramic Basin 1 Tap Hole - White
84699 nuie 1 Tap Hole Ceramic Basin with Deep 40mm Profile 800mm
84702 Classique Components Fireclay Classic Basin 1 Tap Hole, 500mm - White
84703 Classique Components Fireclay Classic Basin 1 Tap Hole, 600mm - White
84705 Classique Components Fireclay Classic Basin 3 Tap Hole, 500mm - White
84706 Classique Components Fireclay Classic Basin 3 Tap Hole, 600mm - White
87878 nuie Mayford Round Ceramic 1 Tap Hole Basin 1050mm
87946 nuie Asselby W.C. Pan Close Coupled
87947 nuie Provost Short Projection Pan
87949 nuie Lawton Short Projection Pan
87951 nuie Lawton New Pan
87956 Hudson Reed Arlo Close Coupled Short Projection Pan
87958 nuie Ambrose Close Coupled Short Projection Cistern & Fittings
87986 nuie Bliss Square Pan
87996 nuie Provost Pan
88003 nuie Harmony Pan without Seat
88025 nuie Ivo Comfort Height Close Coupled WC Pan
88028 nuie Legend Pan & Seat
88040 Old London Richmond Comfort Height Toilet Pan Close Coupled Excluding Seat
88043 Old London Richmond Comfort Height High/Low Pan Excluding Seat
88046 Old London Richmond Low Level Cistern B Ceramic Lever Fittings
88067 Hudson Reed Maya 550mm Basin 1 Tap Hole
88068 Hudson Reed Maya 650mm Basin 1 Tap Hole
88069 Hudson Reed Maya 850mm Basin 1 Tap Hole
88073 Hudson Reed Luna Back To Wall Close Coupled Pan
88074 Hudson Reed Luna Wall Hung Pan
88075 Hudson Reed Luna Back to Wall Close Coupled Cistern
88077 Hudson Reed Luna Round Back to Wall Pan
88080 Hudson Reed Arlo Compact Close Coupled WC Pan Back to Wall
88081 Hudson Reed Arlo Square Wall Hung Pan
88082 Hudson Reed Arlo Compact Close Coupled Cistern
88140 Old London 600mm Traditional Basin 1 Tap Hole
88141 Old London 800mm Traditional Basin 1 Tap Hole
88144 Old London 800mm Traditional Basin 3 Tap Hole
88512 Furniture Mid-Edge Ceramic Basin 1 Tap Hole 800mm
88516 Furniture Thin-Edge Ceramic Basin 1 Tap Hole 800mm
88519 Furniture Curved Ceramic Basin 1 Tap Hole 800mm
88938 Hudson Reed Solar 800mm Polymarble 1 Tap Hole Basin - White
88939 nuie L Shaped 1 Tap Hole Polymarble Basin - Compact 503mm
88940 nuie L Shaped 1 Tap Hole Polymarble Basin 503mm
88941 Hudson Reed Quartet 1 Tap Hole Polymarble Basin 720mm
89982 BC Designs Victrion Close Coupled Cistern & Fittings - White
89983 BC Designs Victrion low/Medium Level Cistern - White
89984 BC Designs Victrion High Level Cistern - White
91052 500 Classic Basin (540x410x185) 0TH
91053 600 Classic Basin (640x472x185) 0TH