SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ceb3bf0b3f5697a654c0af42fcff724136b7d27c226e95c4d58109b836956816' 
  AND token = 'zP30KaCGrfBPOpdvMlxUSmkSrMgFbGgf0DrP/yuPIRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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