SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7180fa562be370e5460a830dd18b43455145aa8aa8b9e17223be4bcbf8848e9b' 
  AND token = '/jUDXgjcValVxAB9hjl7zKTsMoZjkBn3JDVRyoNfxIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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