SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c81bb3a4c6069e1569e01598c9368bf09469c20e3299e16ed04555a347ac602e' 
  AND token = 'Nv3X2p4o8DuOAcB5pJHqGF/WGHecDyXWMWl4WHlAruI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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