SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d41c32d435f7a8f8cda53bcb3dffe40c41d1cd6f159906fbb7e62270dea6a5d' 
  AND token = 'JpDXOisdbPhTgqdZiCPFWZCFPjhQkUEmp18gE0dRpqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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