// cookies
+---------+-------------------------+------------------+------------+
|   id    |         email           |     cookie       | date_time  |
+---------+-------------------------+------------------+------------+
| int(11) |      varchar(50)        |   varchar(128)   |  int(11)   |
+---------+-------------------------+------------------+------------+
| 1       | jack_2009@gmail.com     | ojer0f934mf2...  | 1467204523 |
| 2       | peter.zm@yahoo.com      | ko4398f43043...  | 1467205521 |
| 3       | matrix_john23@gmail.com | 34fjkg3j438t...  | 1467205601 |
| 4       | peter.zm@yahoo.com      | 0243hfd348i4...  | 1467206039 |
+---------+-------------------------+------------------+------------+

INSERT INTO cookies VALUES(NULL, $email, $hash, unix_timestamp())

INSERT INTO cookies(id, email, cookie, date_time)
SELECT NULL, $email, $hash, unix_timestamp()
FROM cookie
WHERE email = $email AND
      100  >=  ( SELECT count(1) FROM cookies WHERE email = $email )