SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f147eda7be1ca3994950cd23dd4e82e3ac4a3c38ea56b352fdc05cbf9963aaed' 
  AND token = '/yQQ17wts4hMLV8XKxZMdNkbLLZyN2T86840YcRLelM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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