The suspects used a handgun and a knife to threaten the employee, who was uninjured in the incident. They stole an undisclosed amount of cash.
A canine track was unsuccessful, said police.
Both suspects are described as Caucasian.
The suspect with the handgun was wearing a black bandana, blue hoodie, black pants and white Adidas-style shoes.
The suspect with the knife was wearing a pink bandana, green hoodie, black jeans and grey Adidas-style shoes with white tips.
Anyone with information is asked to contact police.