SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd3ffeab060441b54164faa9ebdc8af60505b9956a9bf81669749050c3ecb616' 
  AND token = '6TgEtSvWDjMbbaM2A0G+zhLqjEWQPb7kGFMWbASDoqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}