SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10641f8b3beb38f7847e91893980424c1ec42803cf61b4f3621ef6b359d7c11b' 
  AND token = 'OLKpqfqUwXC9G5QWOkkk0P/VKbQMytyWdKPp/1D47Zc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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