SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c20030619ddc7f563d5337a94a6db22d9ad5bf809719df0bf81b39c8112f7679' 
  AND token = 'gT0SfKFafLsTNJgZtDJfrP4jE2tWmHutGG6TfQOAwPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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