SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a759e164b26f96d9e90655cda9ba69ea58c136ec787af526ff686c03006f13ee' 
  AND token = 'pHTNrGDkIhMftLdKcS7rJCYj16QSZHSB4mlA2nw5Dvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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