SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a720e2e00325a46f9b6b57b4e320944c3979e67436cdfb14cbf8f3a0f75af570' 
  AND token = 'T1IZIYpUyfQMFs7CoPcAHLPC/B5K6+WzFrC+qJwLzZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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