DynamoDB .Net SDK query timed out

I am using the AWS .Net SDK to access DynamoDB in my alexa lambda function. Frequently, (about an hour every day), I get a query timed out error. This is a query that runs every minute from CloudWatch Events and it fetches the value from a table that has only one row. Most of the time it works fine and returns in milliseconds. However, several times during the day it times out. I have tried increasing and decreasing the timeout period, but it does not help. How do I resolve such errors ? What is causing this ? Will it help if I have my DynamoDB within the same VPC endpoint as the lambda ?