Better Option, Upgrade server or add new droplet for Mysql

Hello, I started with the lowest 1Gb Ram 1 CPU plan, but as my site has grown. my wordpress site now has a Real Estate plugin which is sometimes slow due to the amounts of Data it has to pull, I have extensively reviewed with the plugin developer. The database is around 1GB. Issue is since there is around 9K properties, the database has to search thru all that to pull up the property info that was clicked on, so it slows down the site ( I have images hosted elsewhere because of the size over, 90K images ) So if someone can please tell me which of the two is a better option:

1. Upgrade to a bigger plan ( not sure if 2GB plan would be enough ), not sure if its RAM or CPU that is linked to the database processing speed .

2. Create another starter droplet and host only the database there. I searched and read some articles here but only found how to do this only with a new install, not on an existing installing. If this is the better option vs the first option, can someone can please point me to an article on how to achieve separating the database to a separate droplet on an existing installing.

PS: Mysql Cache is enabled / verified via ssh Im using Plesk Onyx 18 Site traffic is low for now, but expecting more, currently about 10 visitors a day performing searches pull database info

Thank You