SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95869c3bff93dec9117df2d33a5db81254b14ebdea2d11fc054318c3717851b6' 
  AND token = 'WC6qhxl/IlD8Mnlwu2lAsJ6OLjt73OpIQAjU+RRqVjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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