SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '485babdea573c61ddb0a45b8421632246a6bf1881cc07c0990555f6f7be8734f' 
  AND token = 'G/HLoF0mwP7BkhsGtz6NTDxzsJ0/PEQJQfG+OcSbxLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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