In the code there is no line. You just have a scalar value x = 456.5844, y = 0.0671.
If one of X or Y is a scalar and the other is either a scalar or a vector, then the plot function plots discrete points. However, to see the points you must specify a marker symbol, for example, plot(X,Y,'o'). Refer to the documentation forplot function.
Also, you are setting theaxis limit beyond the data point.
You can see your data point by executing the following code: