How to improve the following query

Team,

Any suggestions on how to improve the following query.

- avalableInd is a boolean, has a value of 1 or 0.

- I am looking for only one shoeId with certain shoetype and availableInd=1.

select shoeId from (select shoeId from shoeGroup where shoeId in
 (select shoeId from shoe where shoeType=:"SYS_B_0" and availableInd=:"SYS_B_1") and availableInd=:"SYS_B_2")
where ROWNUM=:"SYS_B_3"

SQL> desc Shoe;
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 SHOEID                                  NOT NULL VARCHAR2(100) : primary key
 SHOETYPE                                         VARCHAR2(25)
 avalableInd                                          NUMBER(10)

QL> desc ShoeGroup;
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 SHOEID                                  NOT NULL VARCHAR2(100) : primary key
 ALTTYPE                                            VARCHAR2(25)
 avalableInd                                          NUMBER(10)

Thanks,