SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '883a55cb56428556332ffe7a4cd3c60682547357d6e9518b62be7750a1c65e59' 
  AND token = 'tHypJZrX0ArtPq0zbro/GCvkTrUB/enVDOS2P+Gmtjk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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