SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '213de1a72f50f655d485d11516c203dd2d5ae9e077a7afc2ce3ab3d881dbc571' 
  AND token = 'tMgRjjDaRNxV/+KXnzpwOoGGxi1EPH4dqFfFiSGFlLM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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