SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd242191297fc6c43d2f484c54e59cc6f34a17dda5d3d423d05e61293ddd5f05b' 
  AND token = 'jvwQWuY6PaIjOhSAHeuoFa/8GXlIH7kpvJZ8OPvlssE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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