In my 2008 Toyota Land Cruiser Prado there is a dashboard warning light flashing. They symbol is of a key and it blinks but the car is not starting and is just ticking when you turn the ignition

That is to show that the alarm system immobilisor is on. Shut everything off, close all the doors,windows etc. Lock the car. Then open the car using the remote handset or key and try to start the engine, if it still does not start , then you may have to take it to the dealer to check and reprogramme the system. BTW, did you disconnect the battery prior to this fault ? this would explain why the system is immobilised. Hope that helps