SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f92d620edb32914ecf55ab34322f39f8de615c1e54a8b56f905849b8d7ddb6a' 
  AND token = 'jNaZNJUjitawNP9aplgh8CbUwgTFm9sBjfd5a19WsQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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