SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '861b50f716295bc72e857a4bf7f4972b81423b2f3d429c844ce6d979d33b29a2' 
  AND token = 'b8AwJ4FJgYjP+iQui25oDzSJqZE1wOFqFM5u5rie5Ok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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