SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47751a111e2732bab454fd8513062453e298b07f659eb3f774822c7925d2f8a4' 
  AND token = 'ZwA+BIJJkaAn6qCDbOY20jpgkZXmDvOiCNWO3s1tQdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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