SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04cdf8e1f8db9f2f8a41ed379641e006365436dc3674b943cbfa5ca3687bdac8' 
  AND token = 'DIcQAP94jH21rNAjeDER+5gGqy6p5RH6yu/GQn477KY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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