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, 
  cscart_product_descriptions.unit_name 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 
    84, 85, 91, 90, 86, 87, 88, 92, 89, 99, 
    95, 96, 97, 98, 93, 94
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00114

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost": 0.03464331,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_product_descriptions",
          "access_type": "ALL",
          "possible_keys": ["PRIMARY", "product_id"],
          "loops": 1,
          "rows": 102,
          "cost": 0.03464331,
          "filtered": 26.47058868,
          "attached_condition": "cscart_product_descriptions.product_id in (73,74,75,76,77,78,79,80,81,82,83,84,85,91,90,86,87,88,92,89,99,95,96,97,98,93,94) and cscart_product_descriptions.lang_code = 'en'"
        }
      }
    ]
  }
}