SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c8cd40bda4f9282bfb74806225bbbd628a2b0f09ae779daf871d04d2bb6ab7f' 
  AND token = 'ArZ7R9KuQDLlGfXkkv2MeKpt9b6kPHV9Avi9t4ReZIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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