SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4d7d0487b81f93d58797ecc5c183cce95fd4be98df7736aa967b1c636be40cd4' 
  AND token = 'd8U7BrrM8+MWiHmp+SzkZjzuh1XujRo7QGI1csWjudI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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