SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d35004d7df2715e220a54ac3df0d2e2d194624e0cf073cf0382f4ec182b3a31' 
  AND token = 'ANPPPqnzTIpSdp8xwHQ3R5IN5omNtrFFN/Kfaooz+kw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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