Re: query taking really long time.

[Rick James]

Virtual columns is distracting you from the real problems. Ignore (or remove) `computed_created` and change to

    Select  p.id,
            s.id AS campaign_id,
            p.created,           -- note
            p.response_status_id AS status_id,
            s.seller_id,
            l.name AS lead,
            p.zip,
            1 AS tier_id,
            p.channel_id
        from  ping_post.sell_ping_log p
        INNER JOIN  settings.lead l  ON l.id = p.lead_id
        INNER JOIN  ping_post.sell s  ON s.id = p.sell_id   -- note
        where  p.created >= (curdate() - interval 10 day)   -- note
          AND  s.seller_id = 19       -- note: moved from ON
        order by  p.created DESC;
-- and have these indexes:
--
sell:  INDEX(seller_id, s_id)   -- "covering index"
sell_ping_log:  INDEX(created)  -- this should suffice
lead:  INDEX(id) -- unless you already have PRIMARY KEY(id)

The optimizer may choose to start with `s` or with `p`. I provided indexes for each.

INDEX(lead_id, sell_id, computed_created) is rather useless. The filtering column(s) should be first, not last. You are filtering on `computed_created` (or simply `created`), so it should be first. Since you need a "range" over that column, the subsequent columns will not be used in the index. See http://mysql.rjweb.org/doc.php/index_cookbook_mysql

I am assuming that `created` is of datatype DATE. If not, I may need to alter some of what I have said.

Adding "AND created < cURDATE()" (or using BETWEEN) will not change the performance unless there are a lot of 'future' entries in the table.

Please provide SHOW CREATE TABLE for each table before discussing further.