SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b075a18cd5d4389f1afad0750bad89af72282538943de41ac67292d9d844e20' 
  AND token = 'W585fDQq4QQrSE0jhNovrW9gimXvVu6FwKpSoCnQF9M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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