SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c232901faf0e01bcba116884a9436989be7dd39d159eb692fa911bea452ca468' 
  AND token = '33BVOVl1Fou3uswycqyfjZrX8HZq1x08o4z6gE79TXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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