Look at your shipping template set your transit time to be 2-3 days and ensure your handling time is set to be 1 day or same day to get the shortest shipping time.

SSA shipping templates sometimes offer shorter delivery times as well but you have less control over shipping to remote areas.

Just to note if you have had problems with late deliveries in the past and your OTDR is low then Amazon may pad your delivery times and you can't override this.