The data of table:
1	{'P1-K1':'1-V1','P2-K2':'1-V2'}
2	{'P1-K1':'2-V1','P2-K2':'2-V2'}
3	{'P1-K1':'3-V1','P2-K2':'3-V2'}
4	{'P1-K1':'4-V1','P2-K2':'4-V2'}
5	{'5-K1':'5-V1','5-K2':'5-V2'}
6	{'P3-K1':'6-V1','P4-K2':'6-V2'}

The results of query: SELECT id, mapExtractKeyLike(map, \'P1%\') FROM map_extractKeyLike_test ORDER BY id;
1	{'P1-K1':'1-V1'}
2	{'P1-K1':'2-V1'}
3	{'P1-K1':'3-V1'}
4	{'P1-K1':'4-V1'}
5	{}
6	{}

The results of query: SELECT id, mapExtractKeyLike(map, \'5-K1\') FROM map_extractKeyLike_test ORDER BY id;
1	{}
2	{}
3	{}
4	{}
5	{'5-K1':'5-V1'}
6	{}