SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3ef22b7b50859cdda25813164668877c26c6b852b3b60c2106b6961bc938b992' 
  AND token = '09uQBhpOf0mvHuvDzoHt5PVHAKLpbanLVaXdMVWk9dI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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