SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d1e5d2aeb4fc393ae752e523859dab7156e12263c08cdab817a83f41760dc05' 
  AND token = 'toH2+6N+oR6GoI5RypcfdG5PxbdVxMjQeiPxcGa+vVA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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