SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '959abff980f77d624fc5034cb76830b5f7f1b1ae9c6a55380458eb22b462c93a' 
  AND token = 'DDk5vqpmyKLIjbMS7qKb1lY4Vuu0bmUJClIHBQj2mm8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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