SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86ffc5734262527cf30849ac85a9cedeeecd3b94de66b17e11c4f35bbb94bae8' 
  AND token = 'MSLcT97PhVxT7bLhYeehNDTlFYYVtZQZ9dLhnXrVURo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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