How to write a Schedulable test class

global with sharing class ScheduledBatchable implements Schedulable{
    global void execute(SchedulableContext sc) {
        CronTrigger cronTrigger= [SELECT CronJobDetail.Name, PreviousFireTime, State FROM CronTrigger where State = 'EXECUTING' AND CronJobDetail.Name like 'Email%'];
        List<Payroll__c> payroll = [SELECT Id, FORMAT(Row_DateTime_API01__c),Row_Text_API05__c,Row_Text_API06__c,RecordType.name,
                                    FROM Payroll__c WHERE  Row_DateTime_API01__c =: cronTrigger.PreviousFireTime];
                PayrollSendEmailBatch payrollSendEmailBatch = new PayrollSendEmailBatch(payroll); 
                Database.executeBatch(payrollSendEmailBatch,200);
     }
}

#Test Classes