MySQL table design for keeping short life data

Our application deals with different types of data, one of them - data with 15 minutes life cycle. This data is being fetched, placed into db and then every 15 mins items are deleted if they are older then 15 mins. We had no problems un开发者_StackOverflow社区til we got ~100k data rows in 15 mins, now deletion seems to block database(or exact table only, i'm not sure) for a while.

What is the right way to add and remove huge amount of data in MySQL - should we use in-memory tables, separate db quick data or smthing else?