SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e66d2c68ffc160c4aa0634f605e233b8a04006f864a670a4cf13a185f24be9dc' 
  AND token = 'Hej2picX8PBusi08N4p5cbhVaU3v/Bht3eVuHvLgf8U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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