The Black Stars will face Egypt at Stade de Port-Gentil on Wednesday following separate 1-0 wins over Uganda and Mali in their first two matches.
Egypt need at least a draw against the Black Stars, and hope that result from the other group game goes in their favour to have a chance of reaching the last eight.
“Games between Ghana and Egypt are always difficult games," Afful told pressmen.
"For us, we just want to keep on winning.
“We want to maintain a 100 per cent record, so it is important we go all out and get a win.
“We said to ourselves we were going to win all our games at the
"We have so far won two, so we have to win this one as well.
“We have already qualified, but as I said, we want to maintain a 100% record, so we will go all out.”
Ghana captain Asamoah Gyan and deputy skipper Andre Ayew have also stated their desire to end their group campaign on a high.
The Black Stars, depending on their ultimate position on the group table, will face DR. Congo or Morocco in the next round.
Wednesday's match comes two months after Avram Grant's men suffered a 2-0 away defeat to Egypt in 2018 Fifa World Cup qualifying in Alexandria.