SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '69a9eeb8df331f3c1bdb57c375fbe42e88d2e5efd41324b59e89e4d7d4122ed8' 
  AND token = 'VftHl2BM2to9Embv/VImRoFy7I8tYamxlYBbSqkvHg8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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