SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abbcf353e818a46fe17b73ac9abce4d5a89d6b99f873fb65931e974956526e69' 
  AND token = '4dNr9A7qz6lu2K/5iOgWvOUWt7jjIjRQ+nDm0K+zYG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00076

JSON explain

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