SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19b4f40f5bc8fb1df9c947faf1b35b64d1c14075cd2f24f79873bd0d2272eb27' 
  AND token = '0sLpG1Q/+r6KbpRDZPHeZWAn0UpIahw6CFbjZx5RVks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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