SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7a107d92bd6c49322505a33de330641b8cf326109987cd8b392dee1c163445d3' 
  AND token = '3uwQxmMhPEGtfYkJzzhrsEdWhKEEhZlS7mZf2twfFFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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