Not sure if you have enough time before your flight, you might want to have a look at a Russian transit visa, as a low-cost insurance policy in case you did have a snafu. It would allow you to be rebooked on flights out of SVO or VKO as well.

You did not mention whether you are flying the same route on the return, if that were the case, getting the double-entry transit visa would cover you in the unlikely case of a double whammy, lightning strikes twice.