SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '612a2dc5838fd192d4061abe5db0528ff230ad892efddc8277047e20481b9d39' 
  AND token = 'HTVmnjUWRsqKknsMa8YusYne60TEdpwo/txHDlgxLoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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