SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd51a1a445e07847ccfe12b3161409bda9ae8a692ba13a49605e5520d7c5e6d5b' 
  AND token = 'vwedKv+rytr1ME8MFnR4aNvOGD/83lhdjH0t/nroS4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00065

JSON explain

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