SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '192704adf6818e257f1de1aba620f292540a9a4ed792b962379f993a4c6d7d38' 
  AND token = '7NhRCVm4Mcny44OPJ2I6fb6+AjkRSlgq3UZcZgEfjzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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