SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a839abf9037dd11a3a17124902b27e9d6cc2566c8d309a47f14e5d7f55730e0' 
  AND token = 'Z6Q5/+X8m/XDY779pAAsCVhoyqWJSZv/QtmnvRWKzl4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}