Store IP addresses as INT, not CHAR – by using INET_ATON to convert from a string to an integer and by using INET_NTOA to convert from an integer to a string
Use non-persistent connection, since they are light-weight – much faster create than compared Oracle or PostgreSQL
Use the right storage engine; this means for example the ARCHIVE-engine for logs and other kind of INSERT-only operations, and the MEMORY-engine for fast in-memory data that should go away on server restart