id   name   value   date
a    last   jones   2018-04-03 01:00:00
a    last   smith   2018-04-03 03:03:03
a    last   johns   2018-04-04 02:02:02
b    last   johns   2018-04-03 12:12:12
b    last   smith   2018-04-04 03:03:03
c    last   smith   2018-04-03 11:11:11
c    last   johns   2018-04-03 17:17:17
c    last   jones   2018-04-05 01:01:01

SELECT  distinct a.id
FROM    people a
left JOIN people b
   ON (a.id = b.id and a.name=b.name and a.date < b.date)
where b.date is null
  and a.name = 'last'
  and a.value = 'johns';

id
--
a

id
--
b
c

create table people
( id char(1) not null
, name char(4) not null
, value varchar(20) not null
, ts timestamp not null);

insert into people (id, name, value, ts)
values ('a',    'last',   'jones',   '2018-04-03 01:00:00')
     , ('a',    'last',   'smith',   '2018-04-03 03:03:03')
     , ('a',    'last',   'johns',   '2018-04-04 02:02:02')
     , ('b',    'last',   'johns',   '2018-04-03 12:12:12')
     , ('b',    'last',   'smith',   '2018-04-04 03:03:03')
     , ('c',    'last',   'smith',   '2018-04-03 11:11:11')
     , ('c',    'last',   'johns',   '2018-04-03 17:17:17')
     , ('c',    'last',   'jones',   '2018-04-05 01:01:01');

select id
from people a
where not exists (
    select 1
    from people b
    where a.id = b.id
      and a.name=b.name
      and a.ts < b.ts
)
and a.name = 'last'
and a.value = 'johns';

select id
from people a
where not exists (
    select 1
    from people b
    where a.id = b.id
      and a.name=b.name
      and a.ts < b.ts
      and b.ts < '2018-04-04 00:00:00'
)
and a.name = 'last'
and a.value = 'johns'
and a.ts < '2018-04-04 00:00:00';