SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fd469442ff0112de90f5cea4d1196d3d07a85e4c12a42e19c76ad0dde34aaac' 
  AND token = 'FMVpYkWYzS7FWhzjJ5B6HGMxuuQkl8KvqVTI7O2sp7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}