SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a7c265583aee71af4bac66e4d9e1728e5bb221bd3cdb30eaec6b367fdb52b94' 
  AND token = 'ZQvk7uqeBHDFRr7dqb7eaRjdcAyHKZIUIIQWWGB2stA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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