SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '63b44db3ff08615ac0cfd3bacc4ea6df88c375797096f152b579a05359599968' 
  AND token = 'PELeZlYmBC/7oI80f97vfEyZq3fvGcKucMw6IrF8ZjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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