SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8d982e918d7edc43eb8f925cbaf7ec121ebea88015c7bcf395fa3563b9b39119' 
  AND token = '4qgA6KE4yCgVwcdgEzDHFt+3NdfwAnb77J7S/fLEybA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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