SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ea84bdc48c85cc2618dedcc38edc6eb6a300fb8518ad765ab1cadfaa2daee11' 
  AND token = 'hKkffEYphndBSwlUgDm1sbHbCH1TUl21KJLpujOiUQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00084

JSON explain

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