SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '259a98aa35d7db8dc598fb4bb9b6dcbfd60e4b757225c35b0cfabfd61d328f82' 
  AND token = '1JPuLs54/iLBhNmq+6SBlzCi/nsho01qTVH/Hw8NjWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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