Apex domains cannot have CNAME records.
Question and response
Question
dig SPD-MGTS.RU. NS
Answer
spd-mgts.ru. 3 NS ns3.spd-mgts.ru.
spd-mgts.ru. 3 NS ns1.spd-mgts.ru.
Authority
The response has no authority records.
Additional
ns1.spd-mgts.ru. 3 A 62.112.98.50
ns3.spd-mgts.ru. 3 A 62.112.122.20
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0