Taking massive time slices from the database

Good day
It appears that we are having a problem with serving our ads on our website, which has caused our database to crash a number of times.
We have narrowed down the problem to Ad_Rotate taking massive time slices from the database, while running these queries:

mysql> show processlist \G
*************************** 1. row ***************************
Id: 96967
User: avsa
Host: localhost
db: avsa
Command: Query
Time: 54
State: Sending data
Info: SELECT timer FROM wp_adrotate_tracker WHERE ipaddress = ‘105.228.159.187’ AND stat = ‘i’ AND
*************************** 2. row ***************************
Id: 96968
User: avsa
Host: localhost
db: avsa
Command: Query
Time: 54
State: Sending data
Info: SELECT timer FROM wp_adrotate_tracker WHERE ipaddress = ‘105.228.159.187’ AND stat = ‘i’ AND
*************************** 3. row ***************************
Id: 96969
User: avsa
Host: localhost
db: avsa
Command: Query
Time: 54
State: Sending data
Info: SELECT timer FROM wp_adrotate_tracker WHERE ipaddress = ‘105.228.159.187’ AND stat = ‘i’ AND

You can see that they are taking upwards of 54 seconds to complete these which should not be the case.

Are you able to assist and would any of the following options be a better solution:
– Is there a way to serve ads the way we are currently doing that will be less taxing on the server?
– Is it possible to synchronise the serving of ads on a page, so that every ad request fills the four positions with the same ad set?
– Is it possible to serve ads statically on a round robin basis per unique visitor?

The page I need help with: [log in to see the link]