SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32cc9b4ef2a4df8548f38db43de83a582ba457b9788949b5d7a99bbb2d69885b' 
  AND token = 'P4jEjCgJi3HG3jAg3ZaXaBvC4nHvpcsMqlnlmzuV/Pg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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