Since Today gave me two Silver keys for tokyo bonus via recommended quests, I got 5 total to compare to the weekly tokyo golds I get per character.
Starting Level and EXP Bar
After 5x Tokyo Silver Keys
Using 1x Tokyo Gold Key after
Using 2x Tokyo Gold Keys after the 1x Tokyo Gold Key
As you can plainly see, 5x Tokyo Silver Keys gives more EXP than 1x Tokyo Gold Key. I just wanted to give proof.