SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72ec2d352ea2f271669fd74cfa6912154abe7bada8a77eed2d8e152b27e76186' 
  AND token = 'YsK1GfbHSOO4a4+TklBmm/85BfahrkBkM/DjhUMmgOM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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