There only appears to be a discharge. Ideally there should be a shut off valve, and vent. Otherwise with no vent you will likely get odours eminating. But if I had to guess I would say it a laundry pumping out to a dry well. If there is no basement bathroom then again its likely laundry.
You are not require to open sealed sewage ejector sumps.
Typical sump pump install. Every home in my area built after around 1980 has been required to have one installed. Drain tiles under and around the basement flooring direct water away from the foundation to the sump pump and the water is discharged. With newer construction the water is sent to a drain system, normally the storm, older system’s pump right into the yard.
They can be sealed or not, no matter. Sometimes there sealed to help prevent gases…radon…from entering home.
Life of a sump pump could be any where from 1 day to 100 years. Recommend a back up system…battery, or water powered.