SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2478b3ce5bf8ac7519e02a5b9567d892a63fb8a4b9bd3fdbbef7f8224c0ec6cf' 
  AND token = 'CYxp0wZ1gxrp4vutjgUpdfmjj74USBiJhUiS10QKPjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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