SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cbd073d798743fe8f1f49c6aaf7d5ae32539c5fe641a5dd7daa2966e008af67' 
  AND token = 'jBhB6ECbOckjseovdmVRF0QPa1K9ZmzVu4wF+hfhUVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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