SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4b8982725edfa1b59b3cf522c1e5b9e60f189d8e879841248a458f5eb18588e' 
  AND token = 'wuVH6wpQHIhUsPLn07m2CFfaSG+JMH7qn6DRdCVNeNA=' 
  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