Using datetime

import datetime

mjd = 51_544 + (datetime.datetime(2018,1,16, 2,19,40, 195) - datetime.datetime(2000, 1, 1)) / datetime.timedelta(1)
# 58134.096990743

jd = 2_451_545 + (datetime.datetime(2018,1,16, 2,19,40, 195) - datetime.datetime(2000, 1, 1, 12)) / datetime.timedelta(1)
# 2458134.596990743

For the reverse conversion from JD to UTC see https://stackoverflow.com/a/79807419/11769765.