SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '958190894b674d399df82109d080cf77cf52ce6473022f318d9a15673b73ede8' 
  AND token = 'p/8VDyVr071WFLUh76TUdzDigjVFmsp63trQw6Vd1vY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00066

JSON explain

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