SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8a56529b86ac1bd37dd0937ab72bc498bc436d0b96429b7c61913e3395053ab' 
  AND token = '3pWVYD2SLgE/bLbxEPqHYs7zOqkDtZ8K+0IaIPh8kFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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