I would recommend you to use steem.js (getAccountHistory):
steem.api.getAccountHistory(account, from, limit, function(err, result) {
console.log(err, result);
});
and then filter by op "vote". I've never used SteemSQL but that could be another fast option. I think SteemData Web API would also work but in my tests the performance wasn't stable enough to use it as a reliable service.
If you only need the data for details about self upvoting you could also use getAccountVotes, but I'm not sure about the limit and performance for very active accounts:
steem.api.getAccountVotes(voter, function(err, result) {
console.log(err, result);
});