SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cad5342c302b70b4041937686a15f34c9dbc380b9fccb43269f63fbe00acd19' 
  AND token = 'osXaXBS82OmXOl1iWrr6TIx8aIU7EkeNe1bUF0RiGtc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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