SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b1bad6be453fab12347fdae4f0a7ba026b6ffed053d6980b03a46bc8079a4e9' 
  AND token = 'JKzT3cGJmlgKNuy8pZdpYkZQFtECShZB4tD+cbnHHLk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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