SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da486c6e978d075fc123fd7a3c667cff2eb78b068aef9cb98f381172dd4bb9d3' 
  AND token = 'lP+T+Tgj5O2b6Plr9ckS2zuD/UWlCscSGeQVDUu8u+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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