SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c308a1723a8426545bc2b8d89d9a71ab976e2eddbaa20673a225a68a441d046' 
  AND token = 'VLwwPsaJ/1gh14bq8a1oq9pNKZSvIsYvpRA9djG9gZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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