SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99d27ad94c3da6c704d3a07f7b425f1bcaf0c5e8a3434c7f4d36abc2b0408a92' 
  AND token = '46ncsXqs1SIZVRzMPOQCLwqibilVuLLkvZyeH6fzmSM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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