According to the ifixit LG Gram 15" Repairability Assessment guide, there is a thin film insulator (see Step.8), between the keyboard and the rest of the internal components in the laptop.
You may be lucky that this has prevented the water getting through the keyboard and creating any more damage to the laptop.
If no further problems arise which may make it necessary to open the laptop and check for any water damage to the other components, then it may be worth trying to replace the faulty keys rather than the whole keyboard and see if that resolves the problem.
Hi @Lord Aymor
You have to disassemble the laptop (user the teardown guide) and then remove all traces of water and any corrosion caused by the water by using Isopropyl Alcohol 99%+ (available from electronics parts stores).
Here's a link that may help with this Electronics Water Damage.
Also when opening the laptop, remember to disconnect the battery from the motherboard as soon as it is accessible so as to prevent or at least minimize any possible electrical damage to the motherboard when using tools etc to further disassemble and to clean. There is always power available on the motherboard even when the laptop is turned off as the power button is not a power isolating button. It merely signals the BIOS on the motherboard what is wanted. With any electronics repair it is always power off first, on last
If doing all this seems too daunting to do yourself, contact a reputable, professional laptop repair service, experienced in liquid damage repair and ask for a quote to repair the laptop.