SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8482427a43282d6498fd58fbc03ab4dd4121def7bf1a8cd6383bd2fd4ac95046' 
  AND token = 'hFlVamfYj/zWqWnvwI4TIhYJb4bLoli1zB5/eu7GAoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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