SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'febf93ccc6265fe66f57639309970a13dd82b6f740b0a5685cad49d9f1c7a598' 
  AND token = '1JziFRdCqVpIqVF72kt4ZHwvPape38kehXQpZW8PC9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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