CL-USER> (make-instance 'sb-mop:funcallable-standard-object)
#<SB-MOP:FUNCALLABLE-STANDARD-OBJECT {101188AB4B}>
CL-USER> (sb-mop:set-funcallable-instance-function * (lambda () 42))
#<FUNCTION (LAMBDA ()) {52CFC18B}>
CL-USER> (time (loop repeat 100000000 do (funcall **)))
Evaluation took:
  0.327 seconds of real time
  0.326968 seconds of total run time (0.326968 user, 0.000000 system)
  100.00% CPU
  1,146,664,907 processor cycles
  0 bytes consed
  
NIL

CL-USER> (time (loop repeat 100000000 do (funcall (lambda () 42))))
Evaluation took:
  0.036 seconds of real time
  0.033987 seconds of total run time (0.033987 user, 0.000000 system)
  94.44% CPU
  118,962,455 processor cycles
  0 bytes consed
  
NIL