SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a660097ab65e0834a53b041c0991d5707c2ec4a48b0abd5ad1aeebc76f56d89' 
  AND token = 'IVNyqiIoEp4Asex1VXIkYvrnuX2AadvCxVitCUExDmM=' 
  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"
    }
  }
}