I have found:
edit ethernet-switching-options secure-access-port
set interface ge-* mac-limit 1 action drop
set interface ge-* allowed-mac <MAC>
So if sometinging is going on I would have message like this one:
ESWD_MAC_LIMIT_ALERT: MAC limit is less than the current number of MACs for the interface. You might want to remove some of the MACs for interface ge-0/0/10.0 using `clear ethernet-switching table' command