SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cda5495b38b5f70d981d98eb541999da08bd0d1bb3cdf2db70d02d36e4487cd6' 
  AND token = 's8Fh/XmKYqT8BH5DdwzYZSgfrzoHYtBzetrKH8mhyIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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