SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd85b2f1045a5b07c5d11a233ab972d30eb33ee43c9dc5a0f602a3c92439f9d0' 
  AND token = 'oNVU8tVWk//jhktsYqDlOHIL03Bl1hjcBUxy+ab1tNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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