SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba684f2e153d601cfd2ddae6daa720c929ca36d38644101061412d9d8a4a7dd4' 
  AND token = 'SRpklv0xBSHVzVN4EObwsjzoUY3O4tSonsdF5MDWfYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}