select
...
, case when keyword like '%' + @input + '%' then 1 else 0 end as keywordmatch
, case when content like '%' + @input + '%' then 1 else 0 end as contentmatch
-- or whatever check you use for the matching
from
...
WHERE MATCH (keyword,content) AGAINST ('watermelon')
...
order by keywordmatch desc, contentmatch desc