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 (
    92247, 92248, 92249, 92250, 92252, 92253, 
    92485, 92486, 92487, 89738, 85578, 
    91392, 91394, 85655, 91359, 91389, 
    84104, 92010, 92098, 91360, 91357, 
    91387, 92241, 92242, 92243, 92244, 
    92246, 92251, 92483, 92484, 92440, 
    91358, 92186, 92187, 92188, 92189, 
    92190, 92441, 85652, 85656, 91390, 
    85582, 92488, 91388, 92476, 92477, 
    92478, 92479
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00103

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "21.62"
    },
    "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": "16.82",
        "eval_cost": "4.80",
        "prefix_cost": "21.62",
        "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 (92247,92248,92249,92250,92252,92253,92485,92486,92487,89738,85578,91392,91394,85655,91359,91389,84104,92010,92098,91360,91357,91387,92241,92242,92243,92244,92246,92251,92483,92484,92440,91358,92186,92187,92188,92189,92190,92441,85652,85656,91390,85582,92488,91388,92476,92477,92478,92479)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
84104 nuie Binsey Mini Basin Mixer With Push Button Waste - Chrome
85578 Shallow Seal Trap
85582 Exposed Retainer Bath Waste
85652 nuie Series Two Basin Taps - Chrome
85655 nuie Series Two Mono Basin Mixer - Chrome
85656 nuie Series Two Mono Basin Mixer - Chrome
89738 nuie Commercial Basin Taps - Chrome
91357 nuie Kitchen Taps Lachen Mono Basin Twin Lever Round Basin Tap - Chrome
91358 nuie Kitchen Taps Lachen Mono Basin Single Lever Round Basin Tap - Chrome
91359 nuie Kitchen Taps Lachen Mono Basin Twin Lever Round Basin Tap - Matt Black
91360 nuie Kitchen Taps Lachen Mono Basin Single Lever Round Basin Tap - Matt Black
91387 nuie Kitchen Taps Kosi Mono Basin Twin Lever Square Basin Tap & Rinser - Chrome
91388 nuie Kitchen Taps Kosi Mono Basin Single Lever Square Basin Tap & Rinser - Chrome
91389 nuie Kitchen Taps Kosi Mono Basin Twin Lever Square Basin Tap & Rinser - Matt Black
91390 nuie Kitchen Taps Kosi Mono Basin Single Lever Square Basin Tap & Rinser - Matt Black
91392 nuie Kitchen Taps Kosi Mono Basin Single Lever Square Basin Tap & Rinser - Brushed Nickel
91394 nuie Kitchen Taps Kosi Mono Basin Single Lever Square Basin Tap & Rinser - Brushed Brass
92010 BC Designs Victrion Deck Mounted Crosshead Bath Pillar Taps - Chrome
92098 BC Designs Victrion Deck Mounted Lever Bath Pillar Taps - Chrome
92186 BC Designs Bath Wastes Plug & Chain Concealed Bath Waste - Brushed Chrome
92187 BC Designs Bath Wastes Plug & Chain Concealed Bath Waste - Brushed Gold
92188 BC Designs Bath Wastes Plug & Chain Concealed Bath Waste - Brushed Nickel
92189 BC Designs Bath Wastes Plug & Chain Concealed Bath Waste - Gold
92190 BC Designs Bath Wastes Plug & Chain Concealed Bath Waste - Nickel
92241 BC Designs Basin Wastes Push Down Basin Waste (Unslotted) - Brushed Chrome
92242 BC Designs Basin Wastes Push Down Basin Waste (Unslotted) - Brushed Gold
92243 BC Designs Basin Wastes Push Down Basin Waste (Unslotted) - Brushed Nickel
92244 BC Designs Basin Wastes Push Down Basin Waste (Unslotted) - Copper
92246 BC Designs Basin Wastes Push Down Basin Waste (Unslotted) - Gold
92247 BC Designs Basin Wastes Push Down Basin Waste (Unslotted) - Gunmetal
92248 BC Designs Basin Wastes Push Down Basin Waste (Unslotted) - Industrial Grey
92249 BC Designs Basin Wastes Push Down Basin Waste (Unslotted) - Khaki Green
92250 BC Designs Basin Wastes Push Down Basin Waste (Unslotted) - Mushroom
92251 BC Designs Basin Wastes Push Down Basin Waste (Unslotted) - Nickel
92252 BC Designs Basin Wastes Push Down Basin Waste (Unslotted) - Powder Grey
92253 BC Designs Basin Wastes Push Down Basin Waste (Unslotted) - Satin Rose
92440 BC Designs Plug & Chain Concealed Bath Waste - Brushed Copper
92441 BC Designs Plug & Chain Concealed Bath Waste - Copper
92476 BC Designs Basin Waste with Plug and Link Chain - Brushed Chrome
92477 BC Designs Basin Waste with Plug and Link Chain - Brushed Copper
92478 BC Designs Basin Waste with Plug and Link Chain - Brushed Gold
92479 BC Designs Basin Waste with Plug and Link Chain - Brushed Nickel
92483 BC Designs Push Down Basin Waste (Unslotted) - Brushed Copper
92484 BC Designs Push Down Basin Waste (Unslotted) - Black Silk
92485 BC Designs Push Down Basin Waste (Unslotted) - Marble
92486 BC Designs Push Down Basin Waste (Unslotted) - Matt White
92487 BC Designs Push Down Basin Waste (Unslotted) - Polished White
92488 BC Designs Traditional Pull Up Basin Waste - Chrome