SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '579c398724f73a5c79ff935e94d436b0cf4b9a4322f5acf4939697266851a064' 
  AND token = '/A5tQHtrwJwUGtUJ2kK7qs1Ve/mvyfNLmg2zAKlXE8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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