SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '066f3e3725d490248597a7375e98e3daf09d391d300b42da75233e708fe79b00' 
  AND token = 'hxKSV6pWmletwMd5vx6X9dTT6VoJxZhHTQE3psz/OpU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}