SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7b2b8bbe47be647d684bffe9f88790fc559f08fe72e21b45e67b442f7bbe427b' 
  AND token = '5SMDvhGbE/CB89O4tlOpgFHFzo8sTaKUXdZ1gQEmmAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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