SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac73d4df466a3391fbc89a513476275157da4a928711cb0e3a2be69b2d5c964b' 
  AND token = '5jxsPwlsfuoqCxV5m3HrpEKCgEg00Y0Y8nvGqeomGlw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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