SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '258efd3bd29ba787d93b8b177336e35a904d581ed59f3e3732e7f60af0c9172d' 
  AND token = 'ZKH/eZmSCl90lLSXzWFhNa386UD2DAPYlSM+LYnQyRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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