SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ce139265931b58edb09287f8685186dd3458041937a2fd0aa040d4aafb6ddc6' 
  AND token = '6Fr93FF3ynLiEV/FyisBgyYVd1FoGXHuFZuNwZogCQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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