SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdcd14bc330334833f8ac3c2514f11eb2d92f1137e75c061cb56d369389ce2ea' 
  AND token = '6vQr+wgtzf8l6WxPXhL4IoXW+IPMB7py3nKIizvn8Jw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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