SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77ce4367f582952083f45de853a63c1e8ec27b8f70b098ad646d7893be42b5a4' 
  AND token = 'JH4FK5007GpxhhFVqk+GhwKTt+C07XdR3O7uBrzV9Sk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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