SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '589810f7dbb2d442d7880fc28fec8b5e9bc69f69a93425eabf0f33f1a5f61f42' 
  AND token = 'p6KJtIF+5L0jKn6Q0+HGVeYDNKImNJOVcJkQSt5CSuI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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