SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed481b06d77192afe80db3ce522b02e8e5428af43719b67ba6f4e5dc79b07433' 
  AND token = 'M6pmT6BKlfVLm0HC/+u+kpDMtrZwoNW75l8s3zGyV3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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