SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e614264ec84f08cb73f25eae0ab5ace618f5fc89555af92699bcff73488db9a' 
  AND token = '4YZhFHQlDLutFuTSQfSndW7v5ZCv1gwsp5wWmfhDrKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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