SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6298864923661b3577a20f58386bab4497960f90b4a386bb17ed37a25f1e880' 
  AND token = 'fLI4iRkZ58VpRrcvSGXBorDHHztMf5d4gtUebM+LAro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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