SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60eef405c5f718fbdacf4f781fa7070c50dfe5edbf3047f9a38093e55bf19b84' 
  AND token = 'PBVgKo/dbj7rBmOlAQXwysIityYX9UqQshk2DHMprcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}