SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5165f7381afcca921268f3986692342bae29d75f21cfbea371142e3c54d5f91' 
  AND token = 'nOlU3LNEFifgWaQIXIVvwD0pK8SYbW5tEsW0D+FGcEA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}