SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6a093626284b53851fe5e0530bbd02bfbeba80411831e732b90d2bc4cda6ef0' 
  AND token = '5nC+0J+njZoLDHdXvNqdGieAmZcq259hRlr6wISAzpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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