It is possible if your systemd is recent enough to support IP access control:
# /etc/systemd/system/check_mk.socket
# systemd socket definition file
[Unit]
Description=Check_MK Agent Socket
[Socket]
ListenStream=6556
Accept=true
[Install]
WantedBy=sockets.target
# /etc/systemd/system/check_mk.socket.d/10-ipacl.conf
[Socket]
IPAddressDeny=any
IPAddressAllow=10.0.5.5