How to join two query in MYSQL

Question

I have 2 MYSQL base queries which dependent on each other, here are my quires

@$query = "SELECT * FROM coins_tokens";
$row    = $db->Execute($query);

foreach ($row as $rowItem) {
    $name = $rowItem['ct_id'];

    @$sql1 = "SELECT * FROM historical_data  WHERE `name` = '".$name."' GROUP BY name LIMIT  30";
    $row2 = $db->Execute($sql1);
    foreach ($row2 as $rowItem2){ 
        $market_cap     = $rowItem2['market_cap'];
        if($market_cap >= 500000000){

        }
    }
}

It slow down my whole process and take lot of time to execute, as there are more then 1400 results in coins_tokens , then there are more then 600000 records again 1st table, in both table ct_id and name are conman.

And what I am trying to do is to get the currencies which have more then 500million market_cap in last 7 days. So am fetching the currencies from 1st table and there historical data from 2nd table and checking if market_cap there increased in last 7 days.

Here is the structure and data of historical_data table:

Answer 1

SELECT
    c.*,
    d.`date`,
    d.market_cap
FROM coins_tokens AS c
    LEFT JOIN historical_data AS d ON c.ct_id = d.name
WHERE d.market_cap >= '$mketcapgrter'
  AND DATE(d.`date`) >= CURRENT_DATE() - INTERVAL 30 DAY 
GROUP BY d.name 
ORDER BY d.market_cap DESC LIMIT 100