SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38a6dad38201e8c0e6651fcffb57039818ecdef6a686dd3b90b9936d92bfb925' 
  AND token = 'nh1XNXM3oDx1AK94YeQHh+PomAEyN5bspGuuuYZ8z2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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