SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee1fb34a957a9ec955b22a1e174faf4e2cb08a8804e18a636a5d729a19cd374c' 
  AND token = 'INsK3cjJBUJxnuhh2GCb0H09xVmfI+OVyQM8BFGIkrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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