SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41241cbc3735e8b551ef063632e15eee824ae2458c893b3b80a40c5546d15178' 
  AND token = 'JH/IJ5oGBCVDsjs4QfpwarlWRIoqiraPDfFBn4caT5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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