SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7375a32d7e241262999cbefe711b75863ceed1c4ad62f35468438b8dc680b186' 
  AND token = 'FT7wBij+QJFeiXbRmd3so3yeAw8FGMSNj4IbvgX6mU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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