SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68c171155a343eaa8df97dc5424d7cb0e652db1997fecb568d9b1dfd8aa075ff' 
  AND token = 'ifP7KOURWCpJvggPa2vjeocKTrEMvzV42NQohPo/qvA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

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