SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d2e036aa02c3dc5fe7250432859ee656cd8ca10c40843cecf6a00edb0217bc7' 
  AND token = 'nXTXfXX6zWChezol1jO9wARET3UblETAxQn6LAlasvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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