SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '97e3afb42e7d29048458de9d58f836e63754b90c95ae2031e47fbf8de08c4342' 
  AND token = 'VLGEvjplBOVaJ87OCUUglB/z75VcX7/OR6OUwW2BfNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}