Apex domains cannot have CNAME records.
Question and response
Question
dig KES.RU. NS
Answer
KES.RU. 4 NS ns.KES.RU.
KES.RU. 4 NS adns2.south.rt.RU.
Authority
The response has no authority records.
Additional
ns.kes.ru. 4 A 178.34.168.30
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0