MySQL 8.0

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.

create table dates(dte Date);
create index dte_idx on dates(dte);

Records: 0  Duplicates: 0  Warnings: 0

insert into dates values (NOW());
insert into dates values (NOW() + interval 1 day);
insert into dates values (NOW() - interval 1 day);
select * from dates 
where dte = cast(now() as date)
;

dte

2023-08-17

create table datetimes(dtm DateTime);
create index dtm_idx on datetimes(dtm);

Records: 0  Duplicates: 0  Warnings: 0

insert into datetimes values (NOW());
insert into datetimes values (NOW() + interval 1 day);
insert into datetimes values (NOW() - interval 1 day);
select * from datetimes 
where dtm >= cast((now()) as date)
and dtm < cast((now() + interval 1 day) as date)
;

dtm

2023-08-17 08:34:02