SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f7754fd907f9ed71d4b3a12ddfd9464d7537bc56d4a427e9d18be44def0a244' 
  AND token = 'h17sJbr22GYyVMP0Wj/rQ7coUUX/+U9tkHOSCXgMb1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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