SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b08bb330c624a6e28f2fbb4437e5706c3e146774926335a2bfbcb73868927a03' 
  AND token = 'hkXeN07Xs3bWOKXwzOfq+WtmEJVu6yRWq2BKNSp06zI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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