SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd639386461a916957283e26c4c077c20f4e0cca8983a2bac5f39e5752764b868' 
  AND token = 'AIyMgoRtFqxioGCQ2g445fhFZiyrkwJ1w80Ee8HZ+SA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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