SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bdda787b208869f4ba2595a92e4cb5a35f5c5811bdf6ade64fb683967f456b12' 
  AND token = 'p523/puVplFgr/v5DUYwFDaiRRf/I91sbBeKOXJBdCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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