The oil pressure inside an engine is normally around 55-65 psi when the engine is running down the road when the engine is going at a higher RPM.
When the engine is idling the oil pressure may only be around 40 to 45 PSI which it is in my truck when it's idling and sometimes it's around 45 PSI when I'm driving slower.
When I get going down the highway in my truck the oil pressure climbs sometimes to around 65 PSI and sometimes 70 PSI which is also normal.
The faster your engine is spinning the faster the oil pump is spinning as well and as a result your engines oil pressure will rise.
As long as your high oil pressure returns to normal when your RPM of the engine goes down then the oil pump is likely working just fine and nothing is usually wrong with your engine or oil pump.
If the oil pressure stays high as in 80 PSI or above then something may be wrong with the oil pump or something else could be wrong with the engine.