SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14733bfdf43e042ff6f405b68fa905a9e0d826add56afd7a366156e74f7ba0e9' 
  AND token = 'PFcDknGVz+MrDcvYbxxRfh7FGDfqRVjYU/Wek++yt5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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