SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b1043a324e596c62001bd33611eebd682d5ae84c25e6dbc8b6ddf6cce087a2a' 
  AND token = 'zK9Sa44kySsVT5RW/BV+RMfXeXjf7u+HIM6Ewob5L3I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

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