So Shiny

Enchant creature
When this Aura enters, if you control a token, tap enchanted creature, then scry 2.
Enchanted creature doesn't untap during its controller's untap step.

Jumpstart: Historic Horizons

Modern Horizons 2

If So Shiny is itself a token, its enters-the-battlefield ability will trigger.

So Shiny's triggered ability checks whether you control a token after it enters the battlefield to see if it triggers. If you don't, the ability won't trigger at all. The ability will check again as it tries to resolve. If you don't control a token at that time, the ability won't do anything. It doesn't have to be the same token for each check, however.