SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b45913755a4b33c06d99aef2227bad22ab40fe4aa5b8e22cc492513594e36c5' 
  AND token = 'SYiItztpgu2BnSQLwYmpcQYrWs+V/T0chH16CtNvw/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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