SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13423fe3362df26f3503b2e16ed0ba69e4256d9d676e899fdbd09c82f4cf2946' 
  AND token = 'xiMnCOxujopYZIrG6id9u7oFGQGREwd/jWz3McXIq24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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