mysql> create table shop_products (price int);
Query OK, 0 rows affected (0.56 sec)

mysql> insert into shop_products select 1 union select 10 union select 20 union select 5;
Query OK, 4 rows affected (0.15 sec)
Records: 4  Duplicates: 0  Warnings: 0

mysql> create table boffice_user (cena_ot int, cena_do int);
Query OK, 0 rows affected (0.14 sec)

mysql> insert into boffice_user select 2, 12 union select 1,7;
Query OK, 2 rows affected (0.02 sec)
Records: 2  Duplicates: 0  Warnings: 0

mysql> select * from shop_products;
+-------+
| price |
+-------+
|     1 |
|    10 |
|    20 |
|     5 |
+-------+
4 rows in set (0.01 sec)

mysql> select * from boffice_user;
+---------+---------+
| cena_ot | cena_do |
+---------+---------+
|       2 |      12 |
|       1 |       7 |
+---------+---------+
2 rows in set (0.00 sec)

mysql> SELECT shop_products.price, boffice_user.cena_ot, boffice_user.cena_do
    -> FROM shop_products, boffice_user
    -> WHERE shop_products.price BETWEEN boffice_user.cena_ot AND boffice_user.cena_do;
+-------+---------+---------+
| price | cena_ot | cena_do |
+-------+---------+---------+
|     1 |       1 |       7 |
|    10 |       2 |      12 |
|     5 |       2 |      12 |
|     5 |       1 |       7 |
+-------+---------+---------+
4 rows in set (0.00 sec)

mysql>