SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '292ca486bf0d10c3098e9c99cfec41e545a57d81a654dcfa1ceb329d14150860' 
  AND token = 'hIArdMSVZhUC4sRu5VTTP/8tjwvTqAEHXypoiZAiRaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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