SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9263a35d13c9abaf731b4ef2d3e1f2cbd04241c37611620aaed0bd0a787cca8' 
  AND token = 'XWf2ys/nN14gZAyg3QIJbztRcKZG2xeJXs+oIt4AciI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00071

JSON explain

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