SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b1268b6e6fd0a95b8e910186dd812c00bdd32fe2e14764a362d2b13fdf2aecc' 
  AND token = 'Gx7Rl1nbXIABDrpxS+2RT8+vij9GogDau9rUl5xsbls=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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