SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24bebebf6da4576765270dd330b30782c735c28a4e323cdaf42a3545ba08927f' 
  AND token = 'Gola0qRaeh2siEwILPxuwOhHnjPAiE+0dUjvqhxUCV0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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