SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b02ec9e76ac5924e75562c196090189485916574d73718c0c32fe7c33921a4c' 
  AND token = 'hiaACes5FUYwuOJiOFTcqsVdHKoLQsQgqZL0d/DSCjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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