Assuming your flight to ICN is on Asiana Lufthansa First Class Lounges are not available, unless you arrive to Frankfurt in Lufthansa First Class or Swiss First Class flight via ZRH or hold a M&M Hon Circle Card.
You will have access to Lufthansa Senator Lounges (which technically are *A First Class Lounges) and naturally Business Class lounges (although why would you choose one of those...).