SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '186f83f88c0903c004ddae4789b410c9ed164d5f6151fe0818c8a0975e359e24' 
  AND token = 'IO4W+Mz+RQXkvj9iQ+gH3q3qrJMML5UtwHDc49q+whY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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