SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab8d5c7b853b929b91e2c7de9fce04c04eb8b82341884c1cacdbeedf925302c3' 
  AND token = 'StljIuZGNVV4Q/GnrTankEziAcqUjX8Y9PwWxWbsXaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

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