SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2524997605edb958a9428c638547d843bf1a41a999a8ef8ba9da7438cc45b4b0' 
  AND token = 'D/ElBicKciyDdqDkoee9igj4xWbvBY3vM5GR+lr1c0E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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