SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3df997a7046c7161b1bdbc77875221ff8d3a3775e016e7f945b4fc39c51cfb08' 
  AND token = 'pGB7wB0buQQdmnoI+uhjZiwXL30B63zgWVoXVbfFSoM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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