SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dce449d2ad8da5c1f0fdef8011f2299af71fcd4ad791108300a46c59e982eefa' 
  AND token = 'v7rbZIz2vcNnhGOI8iTScIGNsffnP5X7aYN78q2/Zm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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