SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eedeb485b5c34d9fdc37032db9c9bbe212db25701b669f4b210aae38f1d54ad1' 
  AND token = 'sS2PaVv2xvHddwGHeXA2mJzclPvbudCRAEpOkZBGMfY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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