This is more to add to Renan's answer than anything else. He covered the fact that you can't expect Lenovo to foot the bill on this one, and did so very well.
3 months ago
That's part of the issue right there. That, and attempting to get it to work without getting it fixed. That may have bade the difference between just replacing the keyboard, and having to replace the keyboard as well as the motherboard. Time is one of the enemies here. Getting a laptop dry after a spill is paramount, and can still cost you a keyboard. Most of the time there is just no getting the moisture out from between the three layers of plastic that make up the actual working components of the keyboard. At all. Ever.
But you've got 3 months of shorting contacts now. 3 months of making connections that were never supposed to have been made, and you are seeing the results.
So, the keyboard needs to be replaced. That's first. The unit needs to be disassembled, inspected, and possibly cleaned. So, you should expect to pay at the very least, a diagnostic fee and the time to clean the unit... and that's just to find out if it will be worth it to repair. From there, you will face either just replacing a keyboard, or replacing much more as well.