Rules are always viewed and managed per category: open Chart of Accounts, click the Auto-categorization rules icon on a row, and the window shows that category's Keyword Rules and Learned Rules with their Matched counts. There is no global rules page in the current version, so if you are unsure which category a keyword was attached to, check the likely categories (for example Purchases - Food & Beverage and Merchant Account Fees hold the built-in default rules).