SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03829ac20b7d9edff94142ff5ea9e9377474782a4ea06b51f95e6ab9a1710260' 
  AND token = 'sYKqZMBI+pg0wzCubM7mXGQb6rL3iaKhShPx7xs/VUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

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