Syntax:
EXECUTE stmt_name
    [USING @var_name [, @var_name] ...]

After preparing a statement with PREPARE, you execute it with an
EXECUTE statement that refers to the prepared statement name. If the
prepared statement contains any parameter markers, you must supply a
USING clause that lists user variables containing the values to be
bound to the parameters. Parameter values can be supplied only by user
variables, and the USING clause must name exactly as many variables as
the number of parameter markers in the statement.

You can execute a given prepared statement multiple times, passing
different variables to it or setting the variables to different values
before each execution.

URL: https://dev.mysql.com/doc/refman/5.7/en/execute.html

