$tomorrow = strtotime('+1 days');
..
->where(['>=', 'created_at', mktime(0,0,0,date('m'),date('d'),date('Y'))])
->andWhere(['<', 'created_at', mktime(0,0,0,date('m', $tomorrow),date('d', $tomorrow),date('Y', $tomorrow))])
SELECT FROM_UNIXTIME(t.created_at), t.*
from table_name t
where (FROM_UNIXTIME(t.created_at) + interval 1 day) >= now()
$lines = $this->find()
->alias('t')
->where("(FROM_UNIXTIME(t.created_at) + interval :days day) >= now()", [
':days' => $day
])
->all();