Place butter beans, salt, chili flakes, and thyme in a large pot, and cover with cold water. Make sure water covers the beans by at least 1 inch, and then bring to a boil over high heat. Continue cooking for 5-10 minutes, or until beans are tender. Then strain them through a colander and run cold water over them to stop the cooking process. Discard thyme and cool the beans in the refrigerator.
Warm olive in a small pan, and add garlic cloves. Simmer gently until garlic is fragrant. Remove garlic cloves from oil.
Pour lemon juice into a bowl, and slowly add the olive oil, whisking constantly to create an emulsion. Season with salt and pepper.
Toss the butter beans with the celery, lemon vinaigrette, and more salt and pepper to taste. Enjoy!