SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b7f714d2ad2c7468857086d5393a5bb58ae3c0e5758b67dfdc8bca9c7e4df06' 
  AND token = '38zIiwVthKKl3u33M64ZhUvwZVwW0I0VgZKuxgGUssE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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