SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f461b194937bf419f936eb82709d83a64d0337fbcf296960cd9aa34095bfb9f' 
  AND token = 'ETCwRwHouv/PKl97oPi8H95oLVM1fG696ClNSO6Py7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}