SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07e8814500175f3e7df47824b3b82ecda2857266df36e67fd20a05390f8c0543' 
  AND token = '9QhAdzGAFQfmxvMrzXwQDZP0XTVDBBqd7VFH2h9pfYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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