SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a3bb9f2e9bc1653146bbf610ba98b05f4d7e88652931a3a0e3baa9eec3a4883' 
  AND token = 'ju1b9i2JU1XpHzszlOOooLOnI6/7SYAkvwSlDsd5DSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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