SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24dd313a76aa2d86de965a02a1ccb51368e94362e45a8b4dfc6705d0039c76fd' 
  AND token = '1vGoEivyQWCqbcXR2rOgzMftBUCOIQclE3fcE9jobsA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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