SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da98bc11f1cacbf8b86138c6477b5bf6bf1e4c6acd6c247faffc45ff45b2e75c' 
  AND token = 'AnB4bqmzryx2m8T8KMZU6QrSOqzV0xWzR2yRVQuciiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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