SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd3633eb85e3afbd19a0d4224e4f37f495b72ae75fe30c6ecfe627e6f8379440' 
  AND token = 'JXywwC4MMygLzt4oVGDYPvkmICS6xKRKn4ii+LLJPNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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