SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77ea96131de121d7ae794656186eb64a3cfe3c48cee60bd11e06d08a6481cf3d' 
  AND token = 'Bl9C8FZ16k6BLZzc9KMLCFKCZgj4So/EjdYeiOrjfTQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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