SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b3993c5d1f579600f757a5f5fb3d32d2cc783fd3e66eeab36e30c71881a504f' 
  AND token = 'F4W0htA5h3rEDM+j5jIeTw3z+qIWDyj6W2NkUt4MZ5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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