SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17a43c5b8d1fd4196da1e92f62a28a9873127f2119c4f0c081737798409140ce' 
  AND token = 'DA+/ym5SJkbVVkNQcwHskvGj3sBumoQOvVKT0YqABAg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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