SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf1eb550506ee7df234eb8dd87454d147b93f96132c9590ce8e530b3194540d5' 
  AND token = 'NGXQNqZ3ATfiQ85qxEVTrdW80ejvr9Ap6WHds4M1N4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}