SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab08b94fcce36d90c87564159d572a05d36c27d42c851e5afa541f1bd31968b4' 
  AND token = 'gOSeaIt9P0kkqRP54/Gp3HAUcOes+4W2nfQHuIvRy1E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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