DROP TABLE IF EXISTS A;
CREATE TABLE IF NOT EXISTS A (
  PID int PRIMARY KEY AUTO_INCREMENT,
  LOCATION point
  );
DROP TABLE IF EXISTS B;
CREATE TABLE IF NOT EXISTS B (
  LID int PRIMARY KEY AUTO_INCREMENT,
  LSTR geometry
  );

INSERT INTO A (`LOCATION`) VALUES(GEOMFROMTEXT('POINT(0 0)')),
  (GEOMFROMTEXT('POINT(5 5)')),
  (GEOMFROMTEXT('POINT(10 10)')),
  (GEOMFROMTEXT('POINT(20 20)')),
  (GEOMFROMTEXT('POINT(30 30)'));

INSERT INTO B (LSTR) VALUES
  (GEOMFROMTEXT('LINESTRING(0 0, -5 -5, -10 -10)')),
   (GEOMFROMTEXT('LINESTRING(-20 -10, -30 -40)'));

SELECT LSTR FROM B WHERE LID=1 INTO @LN;
SELECT PID FROM A WHERE St_Intersects(@LN, `LOCATION`);