Is using sql INSERT IGNORE bad for performance?

What I am trying to do is when a payment is made, the amount is inputted into an input field and then a loop runs through all the customer invoices and as long as each invoice amount is less than the paid amount, less the deducted invoice amount, it inserts that invoice amount into another table. The problem though is if say half an invoice is paid and the user still has an outstanding balance. To cater for this I did another check which checks if the user after payment has an outstanding balance or not. If not or if in credit, it should then pay off all outstanding invoices as the user has a zero balance and therefore should not owe anything.

To do this, I used INSERT IGNORE. It seems to work but I was concerned that it might be inefficient over time as it has to check more and more records?

           $stmt = $db->prepare("INSERT IGNORE INTO `payment_link` (`invoice_id`, `customer_id`, `amount`) VALUES (:invoice_id, :customer_id, :amount)");
            $stmt->bindParam(":invoice_id", $invoice_id, PDO::PARAM_INT);
            $stmt->bindParam(":customer_id", $this->customer_id);
            $stmt->bindParam(":amount", $amount, PDO::PARAM_STR);
            
            foreach ($invoices as $invoice) {
                if ($invoice->amount <= $this->amount) { 
                    $amount = $invoice->amount;
                    $invoice_id = $invoice->id;
                    $this->amount = $this->amount - $invoice->amount;
                    $stmt->execute();
                    
                } 
            }
            
            if($balance <= 0) {
                 $stmt = $db->prepare("INSERT IGNORE INTO `payment_link` (`invoice_id`, `customer_id`, `amount`) VALUES (:invoice_id, :customer_id, :amount)");
                 $stmt->bindParam(":invoice_id", $invoice_id, PDO::PARAM_INT);
                 $stmt->bindParam(":customer_id", $this->customer_id);
                 $stmt->bindParam(":amount", $amount, PDO::PARAM_STR);
                
                 foreach ($invoices as $invoice) {
                     $amount = $invoice->amount;
                     $invoice_id = $invoice->id;
                     $stmt->execute();
                 }
            }

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