SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '482074d5dca00ba95b92a380967ba971187c25bd4d8943d07f86bfbeb54c28ac' 
  AND token = 'qVVv/QWs0far7XoAYlwxkfTnVnErY+Xzln3KGnnmTIE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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