SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37515a7f69e6cc1ccaf1c535202ac6c7e09d7280a31c80fe13b4f894664cc9eb' 
  AND token = 'dnJjnoEtTFB/DbgG/maZ/2i/0CoFnOqKZnS7CmKaNHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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