SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e8367782c2486c7d0ce14807b0c1bb962a4ebd2e3f0ad24458647564f847bcb' 
  AND token = 'lG9GhhcHJknc9jzPzo2n3ZwVjCjixEVHsagwDOfY940=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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