SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d99e0a6f52343a81803573e9ba3fe13333f76aefaeedcb717d6d726931ea489' 
  AND token = 'vwDQjnS8cwDESLQxNaIO7p6kvgvkQHOcQr/DubH9du4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}