SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c656909ba6dddac922a015ed31579f047ff59fae0e7bf5ef7e3bc59f2f306aa' 
  AND token = '2PqmuY8VFNPYKrRGDsBjoLxE4TlJPuTjzkW4St4DLZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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