SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8467927f309b6368bb70bcf143baeea04f31eeb9854e5fefa7e0c2776d863005' 
  AND token = 'zVNmdwbP75OYDvQeCV1/MsCSLBpl3VQ9Ykp8+iqoIW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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