Police say Ishmon tried unsuccessfully to get cash out of the register before fleeing.
Ishmon didn't speak during a brief video appearance Wednesday in Little Rock District Court. An innocent plea was entered on his behalf, and Judge Alice Lightle set his bail at $500,000.
Prosecutors said the victim picked Ishmon from a photo lineup after police received a tip from a caller who identified Ishmon as the suspect. The tip came after police on Tuesday released surveillance images from the store.
A public defender representing Ishmon at the hearing said he is a student at Arkansas Baptist College studying business management.
Little Rock Police Department Sgt. Cassandra Davis said Ishmon was arrested about 10:15 p.m. Tuesday on a traffic stop near 24th and Adams streets.