SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5eff12086363be09cd769620ffbc69ef521108c66d84b0aaec9b2a6cd68732f2' 
  AND token = 'hKVoYvlOLu5J63E9yrbAZtFjDbZPd5GorWWMkOw9oPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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