SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70dadc5c4e720fd705c0968b1daeda4c5633e130e3ebbc58d324a4f7c64ed2f4' 
  AND token = 'N9eI0fE+QIZxBCz8OYz0ZGMFQ0BO8WsuW1ppABLoGQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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