SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc34f68667f21e617ae1ea7e5149af86e2293041490477f09029d05ec25bdc1a' 
  AND token = '7U85xxYKd9oPpPt1hGkTNRYTrOjkrde6H1xL9fEuvIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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