SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b86eda50bddfc178c416f3e400f2e556528553cecc19690522d8327399b9357' 
  AND token = 'pBqmyBwBLWUdZEBhTJq2pS5OQ8zNg2+pFP3ukMZ36gU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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