SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6601307bf00d43f56665da01cd60985c9a67915cbf1be710b7541233f55403c3' 
  AND token = 'bweToiAAwJwiuqD+mZOmhWaTpvGg8PVZPahA3jeOAyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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