SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ef356711f7962151c340ae89e87bbcce05ea1ab18e53c039ef91320e0d28016' 
  AND token = 'twjOjIWgE14CsKrBya88V9EsUO/os2wy78DQYSdYiBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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