SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df05eccb09764eb85937ae7ea83716b8c45bc7ce4ea9b6972354c10414494786' 
  AND token = 'oAFjrOIbWs8Nb5lJsqlSxXGicL0YW1e+5QnsH6tYxQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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