SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3075feaaef54cb780b44c3ddbf3f89ba864c46b9896a166d79b5bcd441e4e7c7' 
  AND token = 'sVmCtqqo5feiFYJYpGaPR5rDhB4B5RSuu8daiuV3D2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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