If you are looking for keywords that is the least efficient way you could do it
A like '%anything does not use an index
Use a FullText search to index the words
Or write you own parser to index the unique words
You would build up a keywords table
And index the keyword
This is a very efficient query
select id
from keywords
where keyword = 'this'
intersect
select id
from keywords
where keyword in ( 'that','other')
Even with wildcards in the keywords it is still much more efficient than searching the entire text