SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b7d475c90d9290a43ccc88b88fd13d531899d44d4e4d17cd50fee10ba1823df' 
  AND token = '8m7lG14w0iqXSjv8JTY4EZzguYNUBYWO/phdnd8E7AI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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