SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e3ac5860c5d98f4020fc4b742f86c8285e55a81618cc0fa2d349fe48ce961b8' 
  AND token = 'OhpZ4/0z9zXqKW5RNCYRZYkyWlPQJjWmOnpU57mgVWc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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