Case when or If else isn't working

Trying to run sql with case when syntax
```
SELECT     
      CASE 
          WHEN event = 'ABC' AND THEN '1'
          WHEN event = 'XYZ' AND THEN '2'
      END AS ExpireOn
FROM some_table
```
Looks like it isn't supported.

I see only if examples:
```
email IF email NOT IN ("hello")
```
But what should I do if I need else option.

maybe you have even a workaround?