Customers needing tokens that live longer than one hour, often need them for IoT devices. In that case, we recommend using an X5C provisioner.
Tokens are designed to be short-lived, and in Smallstep the longest life for a token is one hour.
The idea with the X5C provisioner is that you would use a certificate in place of a token on your IoT device. This provisioner type is very popular with our IoT customers, as the certificates it uses can function similarly to using a token but have a fully-customizable lifespan and can also contain device-specific information in their properties. Each device call to the X5C provisioner would pass the associated cert/key pair as authentication to renew the working certificate used in TLS. We tend to refer to the long-lived authentication certificate as a device's "birth certificate" since it would live the lifetime of the device and clearly identify the device's information.