SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a719be3155c09e58d8fe041cb24de88675ac8c40f1f49fb184c86bcd3e2364c' 
  AND token = 'v2IiP6iYxSBwcfrSwo/kUBkuQjgDuVGSrK4LY615PJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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