SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4110d19fe7e769441dd8e9939afe185c08c00cd3397cfcafb57ac17ed392bfd' 
  AND token = 'jcPrEBAbw5Z2ScnFIfXCKjggc0V+T/q+ufOqLwIIalM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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