SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '833d9c63463d2f554725668e516bdb5ec6b548976b60cc1d2e112d8ad3f63817' 
  AND token = 'HecYWMx5+kWawHDdIt5ODvhRYbBAO/koJw1n9CQOsvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

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