SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9152e699acf6b7f430b60a8ba6a7af3128ee03fd99204ff1df7bcfcd50838c70' 
  AND token = '2DyniIleh8ixBFanzcR3FReX2IHlDsTs3KyfDJokLoY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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