Creating table schema with pre defined Keywords

Question

Hello, I am creating a table scheme that needs to be well optimized, the reason for that will be tables that will have 3 to 5 million records. The big concern here is with regard to the search, in this case the famous LIKE %%... can not even pass close, because of this at the time of each insertion, 3 keywords will be created based on the main field as a name of something, example:

Dummy table "Cities" for example only with the following fields

id|name|visibility|key_1|key_2|key_3

So let’s insert the city of "São Paulo" as a record, in this case we will have two keywords that will obviously be removed accents (programmatically) and all minuscule.

key_1 = sao
key_2 = paulo

That way a search in a table with millions of records would be like this:

select name from cities
    where visibility = 1 
        and (
            key_1 = 'sao' or 
            key_1 = 'paulo' or
            key_2 = 'sao' or 
            key_2 = 'paulo'
        );

The question is: is this really faster than Full text or LIKE% wildcards? is good practice?

I have seen large companies using this technique, however, I would like your opinion.

Thanks in advance!