SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce6f16f4ade51a981ac46833ae3d8fbf701905f9a3cee968706b0fc2fbf61ae5' 
  AND token = 'VZxQeK+FUed6ZD93iIoSbsVsw6NkXUOmHCFyIhBItg8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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