SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f56e483060766c8a63fda29afcd53b35059bb9a4f3ecc2232648990e27f03cd5' 
  AND token = 'KfuU+y5AAVcFD3UvHQI8+E2bsfHkN5vyfjilG1PnX/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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