SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f09b4876cacbd60946fe7be27947a166069a5f80446167b230562ea75967d8d' 
  AND token = 'Xx6xCZNswhGR9EkdFDXnguCtnIN96eWeC2YAM9MxHFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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