SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f5b8cacd137cb6160c16f993ff8fba487b5edb080930f52db0577df0826e28d' 
  AND token = 'UbuvRt2wZsnE70QrGQuAP69iEB+G35i4qx/nX+ni9+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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