Thanks. I’ve come across a page describing how to execute stored procedure in CLSQL:

if you want just execute stored procedure then (execute-command "sp_bla 1, 2")
If your stored procedure returns table or single value then (query "sp_bla 1, 2")

which is quite similar to Lispworks apart from wrapping the call to the procedure with PL/SQL BEGIN END pair.
(sql:execute-command "BEGIN my_procedure(1, 'foo'); END;")