SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c7cecaf30a43a52f32791c97bead095bdc06692f20e77abb114462e06a61c7f' 
  AND token = 'p/19HhsboHFVQ/9uqtpWrEY2+sWpTgka5PHPB1nuRiU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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