SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8498036497c29abc20fadf021b5a70931708e74ee82d2e43418b131c7f1fca59' 
  AND token = 'S3gr0w7vpZ0HZRnIeJ82t4voQ+Iy7AsK/lcmTqZtBK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

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