SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55fb43a933896c8c4c2f9502c7aa120add3f694ccae0f6c462a2e7fe1a38f673' 
  AND token = 'zHfLkVCESdOv60B5UmFfLZigA/ZY8GmA3J/28RYXYhA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}