SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5691ee8cc7f10a65a77265add5584083c80b37b6943e0f6d73631f9dbaeecbf2' 
  AND token = 'SuEh0no+Z9gM6V/vnqpME9qPOCUTl1yOUIKH4CfoUGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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