SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e24fd3fafbc815e05bbd78ea684c5a24a9fd475c409e7ae19bd633a6cee84249' 
  AND token = 'pZ6/+p8JfCSYBWtD8G1kqxb+MBwvAAdr92/YYrwEUv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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