please find below code --

global class SendemailMSA30days implements Database.Batchable<sObject>,Database.AllowsCallouts,Database.Stateful
{
    List<Account> acclis;
    public SendemailMSA30days(){
    }    
    global Database.QueryLocator start(Database.BatchableContext BC){
        List<ID> idss=new List<ID>();
        String soqlQuery = ''; 
        date todaydate = system.Today();
        acclis=[SELECT ID,Name,MSA_expiry_Date__c,OwnerId,AccountOwnerName__c,OwnerEmail__c,OwnerManagerEmail__c FROM Account where MSA_expiry_Date__c!=NULL];
        System.debug('acclis=='+acclis.size());
        
         //new Code
        List<AccountTeamMember> ATM = new List<AccountTeamMember>(
        [SELECT UserId FROM AccountTeamMember WHERE AccountId =:accid.Id]);
         
        for(Account accid:acclis){
            Date contEnd = accid.MSA_expiry_Date__c;
            Integer dayDiff = todaydate.daysBetween(contEnd);
            System.debug('dayDiff@@'+dayDiff);
            if(dayDiff == 30){
                Id newId = accid.Id;
                idss.add(newId);
            }
        }
        System.debug('idss====>'+idss.size());
        
        if(idss.size()>0){
            soqlQuery='SELECT id,Name,MSA_expiry_Date__c,OwnerId,AccountOwnerName__c,OwnerEmail__c,OwnerManagerEmail__c FROM Account where Id IN:idss';
        }
        else{
            soqlQuery='SELECT id,Name,MSA_expiry_Date__c,OwnerId,AccountOwnerName__c,OwnerEmail__c,OwnerManagerEmail__c FROM Account LIMIT 0';
        }
        System.debug('soqlQuery-------->'+soqlQuery);
        return Database.getQueryLocator(soqlQuery);
    }
    
        
    global void execute(Database.BatchableContext BC, List<Account> scope){
        System.debug('scope==>'+scope);
        System.debug('scope==>'+scope.size());
        String Shivams=Account__c.getValues('Fetchadminsemail').AdminEmailAddress__c;
        String shalets=Account__c.getValues('Fetchadminsemail').BussinessHeadEmail__c;
        System.debug('Email'+Shivams+'-'+shalets);
        List<Id> userlistid = new List<Id>();
        List<User> uslist=new List<User>();
        String AccownerName;
        List < Messaging.SingleEmailMessage > mailList = new List < Messaging.SingleEmailMessage > (); 
        /* for (Account acc: scope) {
userlistid.add(acc.OwnerId);
}
System.debug('userlistid=='+userlistid);
System.debug('userlistidsize()=='+userlistid.size());*/
        List < String > toAddresses = new List < String > ();
        List < String > CCAddresses = new List < String > ();
        CCAddresses.add(Shivams);
        CCAddresses.add(shalets);
        // uslist=[SELECT Id, Email,Manager.Email FROM User where ID IN:userlistid];
        /* for(User c : [SELECT Id,Name,Email,Manager.Email FROM User where id IN:userlistid]){
AccownerName=c.Name;
toAddresses.add(c.Email);
CCAddresses.add(c.Manager.Email);
System.debug('toAddresses'+toAddresses);
System.debug('CCAddresses-111---'+CCAddresses);
System.debug('CCAddresses--111--'+CCAddresses.size());
}*/
        for(Account a:scope){
            //send single emails to these contacts
            Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
            toAddresses.add(a.OwnerEmail__c);
            CCAddresses.add(a.OwnerManagerEmail__c);
            mail.setToAddresses(toAddresses);
            Date dt = a.MSA_expiry_Date__c;
            String dtStr = dt.format();
            System.debug('dtStr=='+dtStr);
            mail.setCcAddresses(CCAddresses);
            System.debug('toAddresses----'+toAddresses);
            System.debug('CCAddresses----'+CCAddresses);
            System.debug('CCAddresses----'+CCAddresses.size());
            mail.setSubject('Reminder for MSA expirying within 30 days');
            String messageBody  ='Hello '+a.AccountOwnerName__c+ '<br/>'; 
            messageBody +='<br/>';
            messageBody +='Your MSA signed with the company,'+a.Name+',is getting expired 30 days from today on '+dtStr+'. Please get in touch with the relevant stakeholders.<br/>';
            messageBody +='<br/>';
            messageBody +='Thank you,<br/>';
            messageBody +='Salesforce Admin';
            mail.setHtmlBody(messageBody);
            mailList.add(mail);
            toAddresses.clear();
            CCAddresses.clear();
            CCAddresses.add(Shivams);
            CCAddresses.add(shalets);
        }
        System.debug('mailList@@@'+mailList.size());
        Messaging.sendEmail(mailList);
    }
    global void finish(Database.BatchableContext BC)
    {
        
    }
}