SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9189279bb9bd9393b972d303db7b8bbe51b7bcb42614bbec845a9d463826af59' 
  AND token = 'aEIUxHeYer24EHNsLzJMnXtmeu0FmJsi/XfHPhNiPoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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