SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '727b6d06a53f0e21fb0e297b53eeee1cde20fe4a4cc4a91dbc3499fec90b2ccf' 
  AND token = 'Ulwq8zKinXXuzZ8c4mx1KA/gV62BgYXUOS715jcSZS8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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