SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47b6bd2a83f809023d09b17eeef61507dc70bbe60659afb2948ddf658a107222' 
  AND token = 'yIfY/Vd0EJsTWd79tNLM1qvEs3R0vneaKnNJcC/2Mpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}