SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0d754b6b8dd0d1b25728499279388ba388ff2f13b541689a70ce0cb97e2d9f9' 
  AND token = 'rHuT09WKakYUmBIdkr8EStkhjxZwdeR+vDzZ02SS0KI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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