SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c204bd3e23255ff6309560241559710528f5a15aea297a733cfb1eeb8d3f6e02' 
  AND token = 'Mfrv0JiXuFLuYmqM3GCjbmIlE1ZgjezeA0l94q9leIE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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