SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e39efe44e8af3e87d8282b9678624d8ece5ada66fdadb1a1f56c3bb4173a987' 
  AND token = 'oqXAOwvpPEO0wJHkhzIbfXmAFKzUMQiPnj2xO6LPHWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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