SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ede532202e004eef3218be47b567e08f9939ad1c471bb67791cb68ef9b14c4c' 
  AND token = 'vNGz0NtWVULOMAdBnB0HmZGwIjqrS6N/+gWDA6HrNTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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