SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '671086dd59e976c523e439da53aaf1908e6309d36c7e6908761f2f0ef6ce371b' 
  AND token = 'szfClOewAXi8TA3jRIXP4RkbXTgA8GKx2cmW/NpFpSI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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