SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa352f646b4d7c203bd73d0e01edbf90b76f6922e880a7436a9d8fc4c3e2298a' 
  AND token = '38CH7803+5l3qO3KSyGAhLM5JBW9wEDryHQBDjO5w3E=' 
  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"
    }
  }
}