Your fine to use it, but what @tam says.I have a large size of tetra bits fish food but its expired by 2022 but still its unopened now tell me is it advisable to use them
OK I shall trash themIt will be a best before, so it could mean it has less nutrients than claimed on the tub so wouldn't feed as the only food but mixed should be fine. If its been opened so could have had mould or similar introduced then I'd say chuck it.