SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd83e8f2652bebebb872539e33f11b17a765ead1f1f026ea9aee1fba53d0f6bf6' 
  AND token = 'CuG3uv/mRpXuFewE6KH3fIIyrOovFz5j+TscM8zNNfg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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