PHP script hanging when connecting to 3rd party API

Is there a reliable way to force a php script to exit, or the connection to a 3rd party site to quit, after a certain period of time?  I need to display updated stock data on our intranet. Since the Yahoo Finance API recently disappeared, I'm now using an API provided by Alphavantage. I don't want to directly display 3rd party data on our site. So my system works in two parts: The first script (fired by a cron, every 15 minutes) gets CSV data, via their API call and stores it in a temp DB. (All tables are truncated at the end of the night.) The second script queries the DB and displays it on our site. Most of the time everything goes smoothly. But occasionally the first script hangs, causing the CPU usage to start increasing, eventually crashing the site.  But I don't understand how the script is running longer than 30 seconds, because "max_execution_time" in my php.ini is set to 30 seconds?  Below is my script. Thank you in advance for any insight you can offer!

<?php

function getData($theTable, $theSymbol) {
	
$theKey = 'ourApiKey';
include('db.php');

// Get the csv file from Alphavantage and parse the data, starting at row 2. (Row one contains the column names)
$theFile = 'https://www.alphavantage.co/query?function=TIME_SERIES_INTRADAY&symbol=' . $theSymbol . '&interval=15min&apikey=$theKey&datatype=csv';

if($theFile) {

$con = mysqli_connect($dbhost,$dbuser,$dbpass,$dbname);

$start_row = 2; //define start row
$end_row = 100; //define start row
$i = 1; //define row count flag
$file = fopen($theFile, "r");
while (($row = fgetcsv($file)) !== FALSE) {
    if(($i >= $start_row) && ($i <= $end_row)) {
$theArray = ($row);
$theArray = array_values($theArray);
// assign variables to column values 
		$timestamp = htmlspecialchars($theArray[0], ENT_QUOTES);
		$open = htmlspecialchars($theArray[1], ENT_QUOTES);
		$high = htmlspecialchars($theArray[2], ENT_QUOTES);
		$low = htmlspecialchars($theArray[3], ENT_QUOTES);
		$close = htmlspecialchars($theArray[4], ENT_QUOTES);
		$volume = htmlspecialchars($theArray[5], ENT_QUOTES);
			
		$timestamp1 = date('Y-m-d', strtotime($timestamp));
		$today = date('Y-m-d');
		if($timestamp1 == $today ) {
		
$query = "INSERT INTO $theTable (timestamp,open,high,low,close,volume) values('$timestamp','$open','$high','$low','$close','$volume')";
mysqli_query($con,$query);
		
}
}
    $i++;	
}


if ($con->connect_errno) {
    printf("Connect failed: %s\n", $con->connect_error);
    exit();
}

$con->close();
fclose($file);

}
}
?>

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