SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f02b1f25bc4f61114b798c4efd710d95733e722cb3d07019d6949a58eaad46e' 
  AND token = '805Gg0HihRrZVaGToYF0uFCFvE22X28psIWqVxBBBsQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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