SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac559b93f010da222211089d9f66403af2fd51b71c2abb2b95fa70cae0b10fcd' 
  AND token = 'PsxjRYgnZsMHEVplTGDJqvIrVqE5C4/fJqY6zGXn3wU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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