SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85beefaaed96e844382593f2255320fa1fea164cf41401634f4c48293cce8c13' 
  AND token = 'hmr+itdWwY4duk2pe17BzLOQS8sZD1U2WAnGeWh4h0E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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