SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d484fa7dba0bb677bb52db858eab7ad5cedcd0a739aeab63ad495a808533e0d' 
  AND token = 'vWwm32FnNRmwmod538LnPaEIWrSqrWGpfxcRAlTuFXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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