SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0bb279e47cb21e86d98f7831ae2fcf05cc3627df3d4a66efab1f0da16971bae' 
  AND token = '3KGIi1KrdYmu8t97YbQn54r9SalJMVTb02gVIqVvYoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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