SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97fea5058373dcb61e89a78bec5d70e8f4ae516006af85025a79a3282a2f075a' 
  AND token = 'gIUVCe2wdNrvqfVs+1GXQ3dCqqhW/yV5ZdFptRMyhzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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