SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b06e18a49f8be93c7ba667c61abeee66255d9a4d4b068034ad7797336e5a0a9' 
  AND token = 'dOPlJQZxolp6SrdJw8uptoxqTc4TmkrNBR3wWuDUOUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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