SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '83a5f1ef0bc4bd865bbeff3663d5e5eca46747bf1c4eb603ffe30524565f6c9b' 
  AND token = 'NokJl3+mZ/6hVhsX/reGoPtGPDNHM/ZU/89eeEpPec0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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