I needed to test lease timeout for a specific host. Rather than lowering the lease time globally for all clients I was able to target a specific MAC address using the following configuration block:

host shortlease_9b7d {
    hardware ethernet 00:5f:16:36:9b:7d;

    default-lease-time 900;
    max-lease-time 900;
    min-lease-time 900;
}