Кто пропустил, то WAF можно настраивать не только на 5, но и на 1, 2 и 10 минутный интервал:

https://docs.aws.amazon.com/waf/latest/developerguide/waf-rule-statement-type-rate-based-high-level-settings.html

Evaluation window – The amount of time, in seconds, that AWS WAF should include in its request counts, looking back from the current time.

Valid settings are 60 (1 minute), 120 (2 minutes), 300 (5 minutes), and 600 (10 minutes), and 300 (5 minutes) is the default.

#WAF