SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1288f9f63f0d4636063b799beba9895c8e47a436c4daaec1eb10950f7fb44c0f' 
  AND token = 'hGt0xWwgvlLmSGgKgi7fo7AiLSKAhKK2WPsOBrCTXlc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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