SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd37a0cc16824befdd8cc6c0aa4afc092c8b26bb5d4c11d748f5c1cab706605b6' 
  AND token = 'IJ/gYRws2LSZDSd3sB6/Emlma9JxQHncg/X3f7WvUJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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