SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f000b02f1f11be64eb9770f4c6d1cd851d3571b6517b7325c523b76ef1ed9c77' 
  AND token = 'M/IZuO/wnG+mULxbhoYFjiLJrFkv1cV2kUglpmGPqw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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