SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc90599ff63b7d8c7dcc99bfbb87b2f6f6713b6b4ca4e4929f7ab8eaf82ee719' 
  AND token = 'Gr/o+LdkTgOWgzgtCtLhSGgr390fJWuWwOJNP9E/81E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

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