SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67e3db7fc4a848631a8852f6806f706bc8dfae27ccc85bc595b46287c6477cbd' 
  AND token = 'LjeI3oN1dMpamwItn0UUngwtZotz37OwXc9CXigM+PE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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