Could this visa become relevant for any future visa applications or
can I simply ignore that it exists?
Absolutely. This visa is a matter of record, and depending on whom Russia shares their database with, it may be accessible to a country to which you apply in the future.
Although you have not traveled on the visa (it is not utilized) in the future if you were to apply for a visa to Russia this will definitely be raised.
It is not something to be ignored; you should rectify this situation. I would approach the Russian Embassy and ask for an appointment in order to explain the situation to them. Your visa will be cancelled (possibly the agency that facilitated your paperwork reprimanded) but most importantly – you will have a record of communication that you can use in the future if/when you are ever asked about visas to Russia.
Credit:stackoverflow.com‘