SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fde8123bf56f725d423a41b434301cbc9c7c99bbfbbc007e7a02e18cb03ebc90' 
  AND token = 'Mm2IE2lt1zoSDvWHDsdxTyYvieEVqlAY9aIe6WzlM90=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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