SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b1a48f412a3b86f3a99bc094df6b37466a51cb9f041b50bbe04c9aef0417a72' 
  AND token = 'trXFWE7fvJx5KdHqzF6UVES2EUZvJKgmI2HoCDL2iBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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