SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd76debfc8a9c8fd1840932db94fd805322284aef47cd606e098ce8f49da0fcd' 
  AND token = '1tev1WijoPUdaxUHlJ2pq1V56ParLwbiQ1GxKqkKOPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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