SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58aa5b997a0bafdda75b3b13183f57b461b731a2a1d1b4fefd149235d8603002' 
  AND token = 'q9ThzRzr6z90cTXTbeayEYVZ8BBJvHcOC4XVQ3lLl1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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