SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5ecd921ed67f9d520b91f99d0f825c5216012d6afaed1e25fea8136039a8e683' 
  AND token = 'YBZ1Y/j7ZB71gecOBokh2HgvCVKwy66VntSrZh7/h14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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