SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a0719fdaccf471869415038f485bae6ec0e274de99a5d0af9eb7769966651bf' 
  AND token = 'QSybfveql08mgw8a7zRirZr8xzWqDXEcauCHdgtNYsI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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