SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '235037b2bf8e17d9f4aea928b7a4cb524565ba6af3efaed45cd5a7ad640de7a3' 
  AND token = 'cbxhOnSNPUVm40yLzXlIz3Qow/Zvjp4/fUsBehGxJYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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