Merseyside Police said the robbery happened at 8.30pm on Thursday, April 3, following the first day of the Aintree festival.
Detectives believe many people may have been in the area having a drink or visiting a local bookmakers ahead of Ladies Day.
– Detective Constable Kevin Reppion, Merseyside Police
This was a terrifying incident for the couple who run this business.
This is popular, well-used shop run by a local, hard-working family.
They are simply trying to make a living yet have suffered the ordeal of two criminals coming in brandishing weapons and stealing their takings.
The two offenders were extremely aggressive and the CCTV shows their total disregard for the victims themselves.
Witnesses should call Sefton CID on 0151 777 3823 or Crimestoppers on 0800 555 111.