If the chosen target becomes an illegal target for Expose to Daylight, the spell doesn’t resolve. You don’t scry 1. If the target is legal but not destroyed (most likely because it has indestructible), you do scry 1.
Legalitet:
Standard: Ej legal
Pioneer: Legal
Modern: Legal
Legacy: Legal
Vintage: Legal
EDH / Commander: Legal
Pauper: Legal
Explorer: Legal
Historic: Legal
Brawl: Ej legal
Premodern: Ej legal
93/94: Ej legal