SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48c6ceacd52674bc3b37c9ae90591da882fa359c5eeda9b555ac90b30393e18a' 
  AND token = 'qmev60mDmJ/vnkRSlnTsezrCawg9VaDXuU4B/aRkZyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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