SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28681573cc4280de98e4ba435a92a5a03c2679f7438e5c6027e70c327689aef0' 
  AND token = 'ENun9jNjg/x3TYgPYWePr9/iRbHsmrCS9bSBjw48L0w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

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