SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fd40d2b7a85939090219d1a74d12199da542cfb17cb596baf785fb64c123e3e' 
  AND token = 'RVkfrKv5Zm49gkhoFwkA1HTMDIJno9mNo888nlRdr/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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