SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e84cfa092d07a55594d95396fdbe447cd5518a9a48ac987fc4aff53042b92881' 
  AND token = 'cJZKBrUsgDrzaXwzU3eCqnOHXZIWeCaKM2hBQS4zUEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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