SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b9f24c8a7a5e8835e3b7d1bd6e8562318c706fba0b5d26960ea48d51440a9e9' 
  AND token = 'KIaz8qCWeWORDCCP1L1eJxoIXUTa1MQ6vaN6pGSxlIU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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