SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '934715a419dc938999fa520a9a4449f5d6561b2ed0f355c8b30d37d12fe164cb' 
  AND token = 'AmRvVzcBrUDusoo5M2ofBbUYZ8tqeWDd/q72Vp/krVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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