SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '7a473226e5addb6cf8aeb00d6a476d049267571a5783c6680a01ee8b42d0f3c7' 
  AND token = 'axwV9EhqwG4l9p6ONsdvUTuQx1Z7yg5lYktICjobD/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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