SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd715ef239ff5b94c77a1b610f9def59320cfe133b9b113ba6ec30987ac662c5b' 
  AND token = 'bk7QhQ1nS0Huw7ex19j2+IsbH8X+WVCkhKunDVjXXtw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Impossible WHERE noticed after reading const tables