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 (
    50216, 41341, 41340, 47922, 47921, 41343, 
    47896, 47924, 47923, 41339, 31965, 
    1972, 36746, 2085, 2304, 5829, 41399, 
    15218, 3765, 3004, 2302, 22143, 18160, 
    4599, 2299, 47895, 3641, 2298, 3767, 
    5826, 4597, 2297
  ) 
  AND cscart_product_descriptions.lang_code = 'vi'

Query time 0.02982

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_product_descriptions",
          "access_type": "range",
          "possible_keys": ["PRIMARY", "product_id"],
          "key": "PRIMARY",
          "key_length": "11",
          "used_key_parts": ["product_id", "lang_code"],
          "rows": 32,
          "filtered": 100,
          "index_condition": "cscart_product_descriptions.product_id in (50216,41341,41340,47922,47921,41343,47896,47924,47923,41339,31965,1972,36746,2085,2304,5829,41399,15218,3765,3004,2302,22143,18160,4599,2299,47895,3641,2298,3767,5826,4597,2297) and cscart_product_descriptions.lang_code = 'vi'"
        }
      }
    ]
  }
}