SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f82a684b1feb49a298e77cada7b22aabc991f24fe93bd6ae75bdf2f4b67b7ed2' 
  AND token = 'XLClmTuOQh8/xmQl58akU99kX6Oo+sm0dDyl3VzEFww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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