SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57f42399d6f2ecf4f1e40d50cc50323d5196dc5ab94e118a10d5ca9a210e9183' 
  AND token = '3LCNzeZ5JlXgzPVvsBMi/q3pRLD1Yg6DN/HsPdW5wFo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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