SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28cae904d7b91ec5f877ba24777f94caca4585b950af54e79e5557b4803ebdee' 
  AND token = 'dl9qSTnSHVNdEuQnok+3A3qVtinkk2ygq0Thqt3uTn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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