SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3b643b53c8b4954b031c0cc2078a3e9fee7fb2a42c5f37aeeab95de75989818' 
  AND token = 'N0pGQGEkMnugrPW9Txeo0tzmyVH4I5v+gRsGzjFwEpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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