Police say armed men in masks walked into Whitestar MTR on Cedarhurst Avenue in Medford around 3:30 a.m., demanded money and started firing.
Nineteen-year-old Taleik Bristel, of Patchogue, was killed. The other three victims were taken to the hospital with gunshot wounds but are expected to survive.
It wasn't clear if the gunmen made off with any cash or merchandise.
Anyone with information about the shooting is asked to call Crime Stoppers at 1-800-220-TIPS.