According to detectives, a man walked into the store at 3:18 a.m., simulated that he had a weapon and made off with cash.
No injuries were reported. The suspect is described as a white man, 30-to-40 years old, and about five-foot-eight inches tall.
He was wearing a black hooded sweatshirt with a Champion logo, tan shorts, black sneakers and white sox.
Police ask that anyone with information regarding this crime call Nassau County Crime Stoppers at 1-800-244-TIPS. All callers will remain anonymous.