SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c1b1b4a6c1d3d3d7eff45c174445d7a4725dbd1332aa5d7e6c668e0a2614c1e' 
  AND token = 'ovAOQTIS4vYJ6REoAYUr9uOvWdhnkw2SKPcJyk2nc0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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