SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d4ea34265ed28622577baf1251ce2c00d54288be02e7da9040fa00a56dbfb16' 
  AND token = 'TsgGVC8LdeIU/00G5WQznNKIcYSouL1yux1ouGdCta0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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