SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdac448273bc24db3671e7c7f47253434303b4d204debef78bf3bfe98a173500' 
  AND token = 'ksXwVvAxXIrurQnKaLPrdiRyqFfK1qfImRqTL9QWLeQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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