SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '469cac336f95c57bd8b894cf67cd36707268694976e803aaa6caabd48ed6b6bb' 
  AND token = '1YVTdmZ8qnTnlAWYSfgEVRsWHV0YmkpRR+Y3K8DXs0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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