Select and update specific mysql data in single query
You can make a SELECT as part of an UPDATE statement, but you can't make an UPDATE part of a SELECT statement. However, based on your example you don't need to, instead you can just do the following:

UPDATE parts
SET keywords = CONCAT(keywords,'Phillips')
WHERE name LIKE '%Phi%'


If you want to retrieve the results after you've updated them just execute the following afterwards:

SELECT *
FROM parts
WHERE name LIKE '%Phi%'