SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7886d0656e6bae0702faa6292d3b818418b61b9cf5af32df758bf1a4922ab18' 
  AND token = 'mNXy4wJmM5OOG0BAaKVTn2j3QntChY3HrySlv2D4nBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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